{ "spore": "profile", "id": "thermocouple-alloys", "spore_version": "0.2", "family": "resistance-and-thermocouple-alloys", "name": "Thermocouple wire alloys (Types J, T, E and N)", "abbreviation": "TC", "role": "positive and negative legs of base-metal thermocouples", "category": "metals", "type": "copper-alloys", "summary": "A thermocouple is two dissimilar wires joined at a hot junction, and the voltage that appears across the cold ends gives the temperature. This profile covers four standard base-metal pairs. Type J is iron against constantan, Type T is copper against constantan, Type E is chromel against constantan, and Type N is Nicrosil against Nisil. The alloy datasheets read in this run give density, melting point, resistivity, strength and maximum continuous temperature for each leg, and ASTM E230 limits of error for each pair.\n", "best_for": "Base-metal temperature sensing where the pair is chosen by range and atmosphere (Type N for stable readings in air above 1000 °C, per Kanthal)", "weakest_at": "Each pair is limited by its atmosphere: the iron leg rusts, sulphur attacks the iron and Nisil legs, and Nicrosil cannot be used in vacuum or reducing gas (Kanthal, Isabellenhutte, Pyromation)", "identity": { "formula": "Four base-metal pairs, each a positive and a negative leg. Type J: iron (nominal C 0.03, Si 0.05, Mn 0.30 %, Fe balance; Kanthal) against constantan. Type T: copper (Aurubis C10200, 99.95 % minimum Cu; used here as a proxy) against constantan. Type E: chromel (nominal 90 Ni, 10 Cr; Concept Alloys) against constantan. Type N: Nicrosil (Ni balance, Cr 14.2 %, Si 1.5 %; Kanthal) against Nisil (Ni balance, Si 4.3 %, Mg 0.1 %; Kanthal). Constantan: Cu balance with Ni 43.0 to 45.0 %, Mn 0.50 to 2.00 % (Matthey CuNi44Mn1).", "designations": [], "source": "kanthal-nicrosil", "where": "Chemical composition table of the Kanthal Nicrosil and Nisil pages; iron composition table of the Kanthal iron page; Concept Alloys chromel nominal composition; Matthey chemical composition table; Aurubis C10200 description" }, "tags": { "environments": [], "stresses": [ "extreme-heat", "extreme-cold" ], "applications": [ "thermal-control" ] }, "properties": [ { "benchmark": "density", "label": "Density, iron leg (Isabellenhutte IRON)", "value": 7.874, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "leg": "iron, Type J positive leg", "temperature": "+20 °C" }, "method": "Reference value printed in the Isabellenhutte leg datasheet", "status": "ground", "source": "isabellen-iron", "where": "Physical Characteristics (Reference Values), Density at +20 °C, 7.874", "source_detail": { "title": "Isabellenhutte: IRON data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/IRON.pdf", "year": 2022, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "density", "label": "Density, iron leg (Kanthal)", "value": 7.86, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "leg": "iron, Kanthal thermocouple iron", "temperature": "not stated" }, "method": "Value printed in the Kanthal physical properties table", "status": "ground", "note": "Isabellenhutte prints 7.874 g/cm3 for the same nominal iron leg; both are kept.", "source": "kanthal-iron", "where": "Physical properties table, Density (g/cm3) 7.86", "source_detail": { "title": "Kanthal: thermocouple iron datasheet", "url": "https://www.kanthal.com/en/products/material-datasheets/wire/thermocouple-wire/thermocouple-iron", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Melting point, iron leg (Isabellenhutte IRON)", "value": 1496, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "iron, Type J positive leg", "pressure": "not stated" }, "method": "Reference value printed in the Isabellenhutte leg datasheet, printed as +1,496 °C", "status": "ground", "source": "isabellen-iron", "where": "Physical Characteristics (Reference Values), Melting point, +1,496", "source_detail": { "title": "Isabellenhutte: IRON data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/IRON.pdf", "year": 2022, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Melting point, iron leg (Kanthal)", "value": 1535, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "iron, Kanthal thermocouple iron", "pressure": "not stated" }, "method": "Value printed in the Kanthal physical properties table", "status": "ground", "note": "The two datasheets disagree by about 39 °C (1535 against 1496). The purity of each product is not stated in the datasheet, so both values are kept.", "source": "kanthal-iron", "where": "Physical properties table, Melting point (°C) 1535", "source_detail": { "title": "Kanthal: thermocouple iron datasheet", "url": "https://www.kanthal.com/en/products/material-datasheets/wire/thermocouple-wire/thermocouple-iron", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity at 20 °C, iron leg (Isabellenhutte IRON)", "value": 81, "bound": "exact", "unit": "W/(m·K)", "scope": "material", "conditions": { "leg": "iron, Type J positive leg", "temperature": "+20 °C" }, "method": "Reference value printed in the Isabellenhutte leg datasheet", "status": "ground", "source": "isabellen-iron", "where": "Physical Characteristics (Reference Values), Thermal conductivity at +20 °C, 81 W/m K", "source_detail": { "title": "Isabellenhutte: IRON data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/IRON.pdf", "year": 2022, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "electrical_resistivity", "label": "Electrical resistivity at 20 °C, iron leg (Isabellenhutte IRON)", "value": 12, "bound": "exact", "unit": "µΩ·cm", "scope": "material", "conditions": { "leg": "iron, soft-annealed condition", "temperature": "+20 °C" }, "method": "Value printed in the Isabellenhutte electrical values table, printed as µΩ x cm", "status": "ground", "source": "isabellen-iron", "where": "Thermoelectrical and Electrical Values in Soft-Annealed Condition, Electrical resistivity at +20 °C, 12", "source_detail": { "title": "Isabellenhutte: IRON data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/IRON.pdf", "year": 2022, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, soft annealed iron leg", "value": 370, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "leg": "iron, Type J positive leg", "temper": "soft, annealed", "temperature": "+20 °C", "dimension": "1.0 mm diameter (datasheet note)" }, "method": "Value printed in the Isabellenhutte mechanical properties table", "status": "ground", "source": "isabellen-iron", "where": "Mechanical Properties at +20 °C in Annealed Condition, soft, tensile strength 370", "source_detail": { "title": "Isabellenhutte: IRON data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/IRON.pdf", "year": 2022, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "elongation", "label": "Elongation, soft annealed iron leg", "value": 28, "bound": "exact", "unit": "%", "scope": "material", "conditions": { "leg": "iron, Type J positive leg", "temper": "soft, annealed", "temperature": "+20 °C" }, "method": "Value printed in the Isabellenhutte mechanical properties table", "status": "ground", "source": "isabellen-iron", "where": "Mechanical Properties at +20 °C in Annealed Condition, soft, elongation 28", "source_detail": { "title": "Isabellenhutte: IRON data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/IRON.pdf", "year": 2022, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "max_service_temp", "label": "Recommended maximum continuous temperature, bare iron wire 3.26 mm", "value": 760, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "iron, bare wire", "wire_size": "3.26 mm", "atmosphere": "air" }, "method": "Guide value printed in the Kanthal table of recommended maximum continuous operating temperatures", "status": "ground", "note": "Kanthal prints these as guide values only; bare wire of 0.25 mm falls to 560 °C.", "source": "kanthal-iron", "where": "Recommended maximum continuous operating temperature, bare wire at 3.26 mm, 760", "source_detail": { "title": "Kanthal: thermocouple iron datasheet", "url": "https://www.kanthal.com/en/products/material-datasheets/wire/thermocouple-wire/thermocouple-iron", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "cte", "label": "Coefficient of thermal expansion, iron leg", "value": 11.7, "bound": "exact", "unit": "10-6/K", "scope": "material", "conditions": { "leg": "iron", "temperature": "20 to 100 °C" }, "method": "Value printed in the Kanthal physical properties table", "status": "ground", "source": "kanthal-iron", "where": "Physical properties table, Coefficient of thermal expansion 20 - 100, 11.7", "source_detail": { "title": "Kanthal: thermocouple iron datasheet", "url": "https://www.kanthal.com/en/products/material-datasheets/wire/thermocouple-wire/thermocouple-iron", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "density", "label": "Density, copper leg (Aurubis C10200, proxy)", "value": 8.9, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "leg": "copper, Type T positive leg (proxy grade)", "temperature": "not stated" }, "method": "Value printed in the Aurubis technical datasheet for C10200", "status": "ground", "note": "C10200 is commercial oxygen-free copper, not a thermocouple-grade datasheet. It stands in for the Type T copper leg.", "source": "aurubis-c10200", "where": "Physical properties table, Density [g/cm3] 8.90", "source_detail": { "title": "Aurubis: Technical datasheet C10200 (Cu-OF)", "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Melting point, copper leg (Aurubis C10200, proxy)", "value": 1083, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "copper, Type T positive leg (proxy grade)", "pressure": "not stated" }, "method": "Value printed in the Aurubis technical datasheet for C10200", "status": "ground", "source": "aurubis-c10200", "where": "Physical properties table, Melting point [C] 1083", "source_detail": { "title": "Aurubis: Technical datasheet C10200 (Cu-OF)", "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity at 20 °C, copper leg (Aurubis C10200, proxy)", "value": 391, "bound": "exact", "unit": "W/(m·K)", "scope": "material", "conditions": { "leg": "copper, Type T positive leg (proxy grade)", "temperature": "20 °C" }, "method": "Value printed in the Aurubis technical datasheet for C10200", "status": "ground", "source": "aurubis-c10200", "where": "Physical properties table, Thermal cond. at 20 °C [W/mK] 391", "source_detail": { "title": "Aurubis: Technical datasheet C10200 (Cu-OF)", "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "elastic_modulus", "label": "Modulus of elasticity, copper leg (Aurubis C10200, proxy)", "value": 117, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "leg": "copper, Type T positive leg (proxy grade)", "temperature": "20 °C" }, "method": "Value printed in the Aurubis technical datasheet for C10200", "status": "ground", "source": "aurubis-c10200", "where": "Physical properties table, Mod. of elasticity at 20 °C [GPa] 117", "source_detail": { "title": "Aurubis: Technical datasheet C10200 (Cu-OF)", "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "yield_strength", "label": "Yield strength, soft copper leg (Aurubis C10200, proxy)", "value": 69, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "leg": "copper, soft temper (proxy grade)", "temperature": "not stated" }, "method": "Nominal value printed in the Aurubis mechanical properties table", "status": "ground", "source": "aurubis-c10200", "where": "Mechanical properties, Soft, Rp0.2 nominal 69 MPa", "source_detail": { "title": "Aurubis: Technical datasheet C10200 (Cu-OF)", "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, soft copper leg (Aurubis C10200, proxy)", "value": 179, "value_high": 262, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "leg": "copper, soft temper (proxy grade)", "temperature": "not stated" }, "method": "Range printed in the Aurubis mechanical properties table", "status": "ground", "source": "aurubis-c10200", "where": "Mechanical properties, Soft, Rm 179-262 MPa", "source_detail": { "title": "Aurubis: Technical datasheet C10200 (Cu-OF)", "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "cte", "label": "Coefficient of thermal expansion at 20 °C, copper leg (Aurubis C10200, proxy)", "value": 17.6, "bound": "exact", "unit": "10-6/K", "scope": "material", "conditions": { "leg": "copper, Type T positive leg (proxy grade)", "temperature": "20 °C" }, "method": "Value printed in the Aurubis technical datasheet for C10200", "status": "ground", "source": "aurubis-c10200", "where": "Physical properties table, Coef. of therm exp at 20 °C [10-6/K] 17.6", "source_detail": { "title": "Aurubis: Technical datasheet C10200 (Cu-OF)", "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "density", "label": "Density, constantan (CuNi44Mn1, Matthey)", "value": 8.9, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "leg": "constantan, negative leg of Types J, T and E", "temperature": "not stated" }, "method": "Value printed in the Matthey physical properties table", "status": "ground", "source": "matthey-cuni44", "where": "Physical properties, Density g/cm3 8.9", "source_detail": { "title": "Matthey: CuNi44Mn1 constantan technical data sheet", "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/CuNi44Mn1_v22E.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Melting point range, constantan (CuNi44Mn1, Matthey)", "value": 1230, "value_high": 1290, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "constantan, negative leg of Types J, T and E", "pressure": "not stated" }, "method": "Range printed in the Matthey physical properties table", "status": "ground", "source": "matthey-cuni44", "where": "Physical properties, Melting point C 1230-1290", "source_detail": { "title": "Matthey: CuNi44Mn1 constantan technical data sheet", "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/CuNi44Mn1_v22E.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "max_service_temp", "label": "Maximum application temperature, constantan (Matthey)", "value": 600, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "constantan, strip and wire", "atmosphere": "not stated" }, "method": "Value printed in the Matthey physical properties table and the main properties text", "status": "ground", "source": "matthey-cuni44", "where": "Physical properties, Maximum application temperature 600", "source_detail": { "title": "Matthey: CuNi44Mn1 constantan technical data sheet", "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/CuNi44Mn1_v22E.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "temperature_coefficient_of_resistance", "label": "Temperature coefficient of electrical resistance, constantan", "value": -80, "value_high": 40, "bound": "exact", "unit": "10-6/K", "scope": "material", "conditions": { "leg": "constantan, CuNi44Mn1", "temperature": "20 to 105 °C" }, "method": "Range printed in the Matthey physical properties table", "status": "ground", "note": "Non-canonical property name; temperature_coefficient_of_resistance is not in the canonical property file.", "source": "matthey-cuni44", "where": "Physical properties, Temperature coefficient of electrical resistance (20-105 °°C), -80 to +40", "source_detail": { "title": "Matthey: CuNi44Mn1 constantan technical data sheet", "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/CuNi44Mn1_v22E.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "cte", "label": "Linear dilatation coefficient, constantan (Matthey)", "value": 14.5, "bound": "exact", "unit": "10-6/K", "scope": "material", "conditions": { "leg": "constantan", "temperature": "20 to 300 °C" }, "method": "Value printed in the Matthey physical properties table", "status": "ground", "source": "matthey-cuni44", "where": "Physical properties, Linear dilatation coefficient (20-300 °°C) 14.5", "source_detail": { "title": "Matthey: CuNi44Mn1 constantan technical data sheet", "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/CuNi44Mn1_v22E.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, soft annealed constantan strip (R360 temper)", "value": 360, "value_high": 460, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "leg": "constantan, strip, soft annealed (R360, H90)", "temperature": "not stated" }, "method": "Range printed in the Matthey mechanical properties table of strips", "status": "ground", "source": "matthey-cuni44", "where": "Mechanical properties of strips, R360 H90 soft annealed, Rm 360-460 N/mm2", "source_detail": { "title": "Matthey: CuNi44Mn1 constantan technical data sheet", "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/CuNi44Mn1_v22E.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "density", "label": "Density, chromel-P (Concept Alloys, Type E positive leg)", "value": 8.73, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "leg": "chromel-P, nominal 90 Ni and 10 Cr", "temperature": "not stated" }, "method": "Value printed in the Concept Alloys typical physical property data", "status": "ground", "note": "The Concept Alloys sheet is for Chromel-P, labelled ANSI KP. Its use as the Type E positive leg is not confirmed by a Type E source read in this run.", "source": "concept-chromel", "where": "Typical Physical Property Data, Density (g/cm3) 8.73", "source_detail": { "title": "Concept Alloys: Chromel-P technical data sheet", "url": "https://conceptalloys.com/wp-content/uploads/2013/10/Chromel-PGMVdatasheet091223.pdf", "year": 2009, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Approximate melting point, chromel-P", "value": 1427, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "chromel-P, nominal 90 Ni and 10 Cr", "pressure": "not stated" }, "method": "Value printed in the Concept Alloys typical physical property data, given there as 2600 F and 1427 °C", "status": "ground", "source": "concept-chromel", "where": "Typical Physical Property Data, Approximate Melting Point 2600 F (1427 °°C)", "source_detail": { "title": "Concept Alloys: Chromel-P technical data sheet", "url": "https://conceptalloys.com/wp-content/uploads/2013/10/Chromel-PGMVdatasheet091223.pdf", "year": 2009, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "electrical_resistivity", "label": "Nominal resistivity at 20 °C, chromel-P", "value": 70.6, "bound": "exact", "unit": "µΩ·cm", "scope": "material", "conditions": { "leg": "chromel-P, nominal 90 Ni and 10 Cr", "temperature": "20 °C", "unit_in_source": "uOhm/cm3" }, "method": "Nominal value printed in the Concept Alloys datasheet; the sheet labels the unit as uOhm/cm3 and it is read as µΩ·cm", "status": "ground", "source": "concept-chromel", "where": "Typical Physical Property Data, Nominal Resistivity (uOhm/cm3) 70.6 at 20 °C", "source_detail": { "title": "Concept Alloys: Chromel-P technical data sheet", "url": "https://conceptalloys.com/wp-content/uploads/2013/10/Chromel-PGMVdatasheet091223.pdf", "year": 2009, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "cte", "label": "Coefficient of thermal expansion, chromel-P", "value": 13.1, "bound": "exact", "unit": "10-6/K", "scope": "material", "conditions": { "leg": "chromel-P", "temperature": "20 to 100 °C" }, "method": "Value printed in the Concept Alloys datasheet, printed as cm/cm/C E-6", "status": "ground", "source": "concept-chromel", "where": "Typical Physical Property Data, Temp. Coef. Of Expansion (cm/cm/°C) E-6 13.1 (20 to 100 °°C)", "source_detail": { "title": "Concept Alloys: Chromel-P technical data sheet", "url": "https://conceptalloys.com/wp-content/uploads/2013/10/Chromel-PGMVdatasheet091223.pdf", "year": 2009, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, chromel-P annealed", "value": 95, "bound": "exact", "unit": "ksi", "scope": "material", "conditions": { "leg": "chromel-P", "temper": "annealed", "temperature": "not stated" }, "method": "Typical value printed in the Concept Alloys mechanical properties table", "status": "ground", "source": "concept-chromel", "where": "Typical Mechanical Properties, Tensile Strength, annealed (ksi) 95", "source_detail": { "title": "Concept Alloys: Chromel-P technical data sheet", "url": "https://conceptalloys.com/wp-content/uploads/2013/10/Chromel-PGMVdatasheet091223.pdf", "year": 2009, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "yield_strength", "label": "Yield strength, chromel-P annealed", "value": 45, "bound": "exact", "unit": "ksi", "scope": "material", "conditions": { "leg": "chromel-P", "temper": "annealed", "temperature": "not stated" }, "method": "Typical value printed in the Concept Alloys mechanical properties table", "status": "ground", "source": "concept-chromel", "where": "Typical Mechanical Properties, Yield Strength, annealed (ksi) 45", "source_detail": { "title": "Concept Alloys: Chromel-P technical data sheet", "url": "https://conceptalloys.com/wp-content/uploads/2013/10/Chromel-PGMVdatasheet091223.pdf", "year": 2009, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "density", "label": "Density, Nicrosil (Kanthal)", "value": 8.53, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "leg": "Nicrosil, positive leg of Type N", "temperature": "not stated" }, "method": "Value printed in the Kanthal physical properties table", "status": "ground", "note": "Isabellenhutte prints 8.50 g/cm3 for its NP Nicrosil; both are kept.", "source": "kanthal-nicrosil", "where": "Physical properties, Density g/cm3 8.53", "source_detail": { "title": "Kanthal: Nicrosil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nicrosil/", "year": 2024, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "density", "label": "Density, Nicrosil NP (Isabellenhutte)", "value": 8.5, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "leg": "Nicrosil NP, Cr 14.6 % and Si 1.30 %", "temperature": "reference value" }, "method": "Reference value printed in the Isabellenhutte Type N sheet", "status": "ground", "source": "isabellen-typeN", "where": "Physical characteristics row, Melting point / Density, NICROSIL NP 1,394 °C / 8.50 g/cm3", "source_detail": { "title": "Isabellenhutte: Thermocouples type N / extension leads type NX", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/Thermocouples%20type%20N_NX.pdf", "year": 2020, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Melting point, Nicrosil (Kanthal)", "value": 1420, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "Nicrosil, positive leg of Type N", "pressure": "not stated" }, "method": "Value printed in the Kanthal physical properties table", "status": "ground", "note": "Isabellenhutte prints 1394 °C for Nicrosil NP; both are kept.", "source": "kanthal-nicrosil", "where": "Physical properties, Melting point C 1420", "source_detail": { "title": "Kanthal: Nicrosil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nicrosil/", "year": 2024, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Melting point, Nicrosil NP (Isabellenhutte)", "value": 1394, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "Nicrosil NP", "pressure": "not stated" }, "method": "Reference value printed in the Isabellenhutte Type N sheet", "status": "ground", "source": "isabellen-typeN", "where": "Melting point / Density row, NICROSIL NP 1,394 °C", "source_detail": { "title": "Isabellenhutte: Thermocouples type N / extension leads type NX", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/Thermocouples%20type%20N_NX.pdf", "year": 2020, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "electrical_resistivity", "label": "Electrical resistivity at 20 °C, Nicrosil (Kanthal)", "value": 1, "bound": "exact", "unit": "Ω·mm2/m", "scope": "material", "conditions": { "leg": "Nicrosil", "temperature": "20 °C" }, "method": "Value printed in the Kanthal physical properties table", "status": "ground", "source": "kanthal-nicrosil", "where": "Physical properties, Electrical resistivity at 20 °C Ohm mm2/m 1.00", "source_detail": { "title": "Kanthal: Nicrosil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nicrosil/", "year": 2024, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "max_service_temp", "label": "Recommended maximum continuous temperature, bare Nicrosil wire 3.26 mm", "value": 1100, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "Nicrosil, bare wire", "wire_size": "3.26 mm", "atmosphere": "air" }, "method": "Guide value printed in the Kanthal table of recommended maximum continuous operating temperatures", "status": "ground", "note": "The same table gives 1250 °C for protected Nicrosil wire of 3.26 mm. Kanthal says the sheet cannot be used in reducing or vacuum atmospheres.", "source": "kanthal-nicrosil", "where": "Recommended maximum continuous operating temperature, bare wire at 3.26 mm, 1100", "source_detail": { "title": "Kanthal: Nicrosil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nicrosil/", "year": 2024, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, Nicrosil wire 2.0 mm", "value": 800, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "leg": "Nicrosil, wire 2.0 mm", "temperature": "not stated" }, "method": "Value printed in the Kanthal mechanical properties table", "status": "ground", "source": "kanthal-nicrosil", "where": "Mechanical properties, wire 2.0 mm, Tensile strength Rm 800", "source_detail": { "title": "Kanthal: Nicrosil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nicrosil/", "year": 2024, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "cte", "label": "Coefficient of thermal expansion, Nicrosil", "value": 17, "bound": "exact", "unit": "10-6/K", "scope": "material", "conditions": { "leg": "Nicrosil", "temperature": "20 to 100 °C" }, "method": "Value printed in the Kanthal physical properties table", "status": "ground", "source": "kanthal-nicrosil", "where": "Coefficient of thermal expansion, 20 - 100, 17", "source_detail": { "title": "Kanthal: Nicrosil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nicrosil/", "year": 2024, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "density", "label": "Density, Nisil (Kanthal)", "value": 8.585, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "leg": "Nisil, negative leg of Type N", "temperature": "not stated" }, "method": "Value printed in the Kanthal physical properties table", "status": "ground", "source": "kanthal-nisil", "where": "Physical properties, Density g/cm3 8.585", "source_detail": { "title": "Kanthal: Nisil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nisil/", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "density", "label": "Density, Nisil NN (Isabellenhutte)", "value": 8.55, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "leg": "Nisil NN, Si about 4.8 %", "temperature": "reference value" }, "method": "Reference value printed in the Isabellenhutte NISIL sheet and the Type N sheet", "status": "ground", "source": "isabellen-nisil", "where": "Physical Characteristics (Reference Values), Density at +20 °C, 8.55", "source_detail": { "title": "Isabellenhutte: NISIL data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/NISIL.pdf", "year": 2019, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Melting point, Nisil (Kanthal)", "value": 1420, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "Nisil", "pressure": "not stated" }, "method": "Value printed in the Kanthal physical properties table", "status": "ground", "note": "Isabellenhutte prints 1341 °C for Nisil NN, so the two sources differ by 79 °C. Both are kept.", "source": "kanthal-nisil", "where": "Physical properties, Melting point C 1420", "source_detail": { "title": "Kanthal: Nisil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nisil/", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "melting_point", "label": "Melting point, Nisil NN (Isabellenhutte)", "value": 1341, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "Nisil NN", "pressure": "not stated" }, "method": "Reference value printed in the Isabellenhutte NISIL sheet", "status": "ground", "source": "isabellen-nisil", "where": "Physical Characteristics (Reference Values), Melting point, +1,341", "source_detail": { "title": "Isabellenhutte: NISIL data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/NISIL.pdf", "year": 2019, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "electrical_resistivity", "label": "Electrical resistivity at 20 °C, Nisil NN (Isabellenhutte)", "value": 36, "bound": "exact", "unit": "µΩ·cm", "scope": "material", "conditions": { "leg": "Nisil NN", "temperature": "20 °C" }, "method": "Value printed in the Isabellenhutte electrical values table, printed as µΩ x cm", "status": "ground", "source": "isabellen-nisil", "where": "Thermoelectrical and Electrical Values, Electrical resistivity at +20 °C, 36", "source_detail": { "title": "Isabellenhutte: NISIL data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/NISIL.pdf", "year": 2019, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity at 100 °C, Nisil (Kanthal)", "value": 27, "bound": "exact", "unit": "W/(m·K)", "scope": "material", "conditions": { "leg": "Nisil", "temperature": "100 °C" }, "method": "Value printed in the Kanthal physical properties table", "status": "ground", "source": "kanthal-nisil", "where": "Physical properties, Thermal conductivity at 100 °C, 27", "source_detail": { "title": "Kanthal: Nisil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nisil/", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "specific_heat", "label": "Specific heat at 20 °C, Nisil NN (Isabellenhutte)", "value": 0.5, "bound": "exact", "unit": "J/(g·K)", "scope": "material", "conditions": { "leg": "Nisil NN", "temperature": "20 °C" }, "method": "Reference value printed in the Isabellenhutte NISIL sheet", "status": "ground", "source": "isabellen-nisil", "where": "Physical Characteristics (Reference Values), Specific heat at +20 °C, 0.50", "source_detail": { "title": "Isabellenhutte: NISIL data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/NISIL.pdf", "year": 2019, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, Nisil wire 2.00 mm", "value": 680, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "leg": "Nisil, wire 2.00 mm", "temperature": "not stated" }, "method": "Value printed in the Kanthal mechanical properties table", "status": "ground", "source": "kanthal-nisil", "where": "Mechanical properties, wire 2.00 mm, Tensile strength Rm 680", "source_detail": { "title": "Kanthal: Nisil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nisil/", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "max_service_temp", "label": "Recommended maximum continuous temperature, bare Nisil wire 3.26 mm", "value": 1100, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "leg": "Nisil, bare wire", "wire_size": "3.26 mm", "atmosphere": "air" }, "method": "Guide value printed in the Kanthal table of recommended maximum continuous operating temperatures", "status": "ground", "note": "Kanthal says Nisil cannot be exposed to sulphur-containing gases.", "source": "kanthal-nisil", "where": "Recommended maximum continuous operating temperatures, bare wire at 3.26 mm, 1100", "source_detail": { "title": "Kanthal: Nisil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nisil/", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "thermoelectric_emf", "label": "Nominal EMF, Nicrosil against Nisil, at 1000 °C", "value": 36.256, "bound": "exact", "unit": "mV", "scope": "material", "conditions": { "pair": "Nicrosil against Nisil (Type N)", "temperature": "1000 °C", "reference_junction": "0 °C, ITS-90" }, "method": "Nominal EMF value printed in the Kanthal table; the Kanthal sheet lists EMF against Nisil at each temperature", "status": "ground", "note": "Non-canonical property name; thermoelectric_emf is not in the canonical property file.", "source": "kanthal-nicrosil", "where": "Thermoelectric properties, Nominal EMF values vs Nisil, 1000 °C, 36.256 mV", "source_detail": { "title": "Kanthal: Nicrosil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nicrosil/", "year": 2024, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "thermoelectric_emf", "label": "EMF of Nisil NN against Cu/NIST 175, at 100 °C", "value": -1.763, "bound": "exact", "unit": "mV", "scope": "material", "conditions": { "pair": "Nisil NN against copper (NIST 175)", "temperature": "100 °C", "reference_junction": "0 °C" }, "method": "Value printed in the Isabellenhutte NISIL sheet", "status": "ground", "note": "Non-canonical property name; the EMF is against copper, not against the Nicrosil leg.", "source": "isabellen-nisil", "where": "Thermoelectrical values, EMF versus Cu/NIST 175 at +100 °C, -1.763", "source_detail": { "title": "Isabellenhutte: NISIL data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/NISIL.pdf", "year": 2019, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "limit_of_error", "label": "Limit of error, Type J, standard (ASTM E230)", "value": 2.2, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type J, iron against constantan", "temperature_range": "0 to 760 °C", "rule": "greater of this value or 0.75 % of reading", "reference_junction": "0 °C" }, "method": "Limit of error printed in the ASTM E230 table reproduced by Pelican Wire", "status": "ground", "note": "Non-canonical property name; limit_of_error is not in the canonical property file.", "source": "pelican-tolerances", "where": "ASTM E230 table, Type J row, Standard column: +/-2.2 or +/-0.75 %", "source_detail": { "title": "Pelican Wire: Thermocouple tolerances", "url": "https://pelicanwire.com/resources/thermocouple-wire-resources/thermocouple-tolerances/", "kind": "web", "license": "Supplier web page (cited, not reproduced)" } }, { "benchmark": "limit_of_error", "label": "Limit of error, Type J, special (ASTM E230)", "value": 1.1, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type J, iron against constantan", "temperature_range": "0 to 760 °C", "rule": "greater of this value or 0.4 % of reading", "reference_junction": "0 °C" }, "method": "Limit of error printed in the ASTM E230 table reproduced by Pelican Wire", "status": "ground", "note": "Non-canonical property name; limit_of_error is not in the canonical property file.", "source": "pelican-tolerances", "where": "ASTM E230 table, Type J row, Special column: +/-1.1 or 0.4 %", "source_detail": { "title": "Pelican Wire: Thermocouple tolerances", "url": "https://pelicanwire.com/resources/thermocouple-wire-resources/thermocouple-tolerances/", "kind": "web", "license": "Supplier web page (cited, not reproduced)" } }, { "benchmark": "limit_of_error", "label": "Limit of error, Type T, standard (ASTM E230)", "value": 1, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type T, copper against constantan", "temperature_range": "0 to 370 °C", "rule": "greater of this value or 0.75 % of reading", "reference_junction": "0 °C" }, "method": "Limit of error printed in the ASTM E230 table reproduced by Pelican Wire", "status": "ground", "note": "Non-canonical property name; limit_of_error is not in the canonical property file.", "source": "pelican-tolerances", "where": "ASTM E230 table, Type T row, Standard column: +/-1 or +/-0.75 %", "source_detail": { "title": "Pelican Wire: Thermocouple tolerances", "url": "https://pelicanwire.com/resources/thermocouple-wire-resources/thermocouple-tolerances/", "kind": "web", "license": "Supplier web page (cited, not reproduced)" } }, { "benchmark": "limit_of_error", "label": "Limit of error, Type T, special (ASTM E230)", "value": 0.5, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type T, copper against constantan", "temperature_range": "0 to 370 °C", "rule": "greater of this value or 0.4 % of reading", "reference_junction": "0 °C" }, "method": "Limit of error printed in the ASTM E230 table reproduced by Pelican Wire", "status": "ground", "note": "Non-canonical property name; limit_of_error is not in the canonical property file.", "source": "pelican-tolerances", "where": "ASTM E230 table, Type T row, Special column: +/-0.5 or +/-0.4 %", "source_detail": { "title": "Pelican Wire: Thermocouple tolerances", "url": "https://pelicanwire.com/resources/thermocouple-wire-resources/thermocouple-tolerances/", "kind": "web", "license": "Supplier web page (cited, not reproduced)" } }, { "benchmark": "limit_of_error", "label": "Limit of error, Type E, standard (ASTM E230)", "value": 1.7, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type E, chromel against constantan", "temperature_range": "0 to 870 °C", "rule": "greater of this value or 0.5 % of reading", "reference_junction": "0 °C" }, "method": "Limit of error printed in the ASTM E230 table reproduced by Pelican Wire", "status": "ground", "note": "Non-canonical property name; limit_of_error is not in the canonical property file.", "source": "pelican-tolerances", "where": "ASTM E230 table, Type E row, Standard column: +/-1.7 or +/-0.5 %", "source_detail": { "title": "Pelican Wire: Thermocouple tolerances", "url": "https://pelicanwire.com/resources/thermocouple-wire-resources/thermocouple-tolerances/", "kind": "web", "license": "Supplier web page (cited, not reproduced)" } }, { "benchmark": "limit_of_error", "label": "Limit of error, Type E, special (ASTM E230)", "value": 1, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type E, chromel against constantan", "temperature_range": "0 to 870 °C", "rule": "greater of this value or 0.4 % of reading", "reference_junction": "0 °C" }, "method": "Limit of error printed in the ASTM E230 table reproduced by Pelican Wire", "status": "ground", "note": "Non-canonical property name; limit_of_error is not in the canonical property file.", "source": "pelican-tolerances", "where": "ASTM E230 table, Type E row, Special column: +/-1 or +/-0.4 %", "source_detail": { "title": "Pelican Wire: Thermocouple tolerances", "url": "https://pelicanwire.com/resources/thermocouple-wire-resources/thermocouple-tolerances/", "kind": "web", "license": "Supplier web page (cited, not reproduced)" } }, { "benchmark": "limit_of_error", "label": "Limit of error, Type N, standard (ASTM E230)", "value": 2.2, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type N, Nicrosil against Nisil", "temperature_range": "0 to 1260 °C", "rule": "greater of this value or 0.75 % of reading", "reference_junction": "0 °C" }, "method": "Limit of error printed in the Isabellenhutte Type N sheet, which cites ASTM E230", "status": "ground", "note": "Non-canonical property name; limit_of_error is not in the canonical property file.", "source": "isabellen-typeN", "where": "Thermoelectric standard tolerances, TYPE N acc. ASTM E230, Standard +/-2.2 °C or 0.75 % (t90)", "source_detail": { "title": "Isabellenhutte: Thermocouples type N / extension leads type NX", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/Thermocouples%20type%20N_NX.pdf", "year": 2020, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "limit_of_error", "label": "Limit of error, Type N, special (ASTM E230)", "value": 1.1, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type N, Nicrosil against Nisil", "temperature_range": "0 to 1260 °C", "rule": "greater of this value or 0.4 % of reading", "reference_junction": "0 °C" }, "method": "Limit of error printed in the Isabellenhutte Type N sheet, which cites ASTM E230", "status": "ground", "note": "Non-canonical property name; limit_of_error is not in the canonical property file.", "source": "isabellen-typeN", "where": "Thermoelectric standard tolerances, TYPE N acc. ASTM E230, Special +/-1.1 °C or 0.4 % (t90)", "source_detail": { "title": "Isabellenhutte: Thermocouples type N / extension leads type NX", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/Thermocouples%20type%20N_NX.pdf", "year": 2020, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "limit_of_error", "label": "Limit of error, Type N, Class 1 (IEC 60584)", "value": 1.5, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type N, Nicrosil against Nisil", "temperature_range": "-40 to 1000 °C", "rule": "greater of this value or 0.4 % of reading", "reference_junction": "0 °C" }, "method": "Limit of error printed in the Isabellenhutte Type N sheet, which cites IEC 60584", "status": "ground", "note": "Non-canonical property name. The IEC 60584 classes for Types J, T and E were not read in this run and are not stored.", "source": "isabellen-typeN", "where": "Thermoelectric standard tolerances, TYPE N acc. IEC 60584, Class 1 +/-1.5 °C or 0.4 % (t90), -40 to 1,000 °C", "source_detail": { "title": "Isabellenhutte: Thermocouples type N / extension leads type NX", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/Thermocouples%20type%20N_NX.pdf", "year": 2020, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" } }, { "benchmark": "max_service_temp", "label": "Upper limit of the usable temperature range, Type J pair", "value": 760, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type J, iron against constantan", "lower_limit": "0 °C", "atmosphere": "vacuum, reducing or inert; oxidising with reduced life" }, "method": "Upper end of the range printed in the Pyromation thermocouple types table, shown as (0 to 760) °C", "status": "ground", "note": "Upper limit of the pair's Pyromation range, not a single-leg property. The lower limit is in conditions.", "source": "pyromation-types", "where": "Type J section, Alloy Combination Iron/Constantan, Temp. Range (0 to 760) °C", "source_detail": { "title": "Pyromation: Thermocouple types", "url": "https://www.pyromation.com/products/Thermocouple/Thermocouple-Types.aspx", "kind": "web", "license": "Supplier web page (cited, not reproduced)" } }, { "benchmark": "max_service_temp", "label": "Upper limit of the usable temperature range, Type T pair", "value": 370, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type T, copper against constantan", "lower_limit": "-200 °C", "atmosphere": "oxidising, reducing or inert, and vacuum" }, "method": "Upper end of the range printed in the Pyromation thermocouple types table, shown as (-200 to 370) °C", "status": "ground", "note": "Upper limit of the pair's Pyromation range, not a single-leg property. The lower limit is in conditions.", "source": "pyromation-types", "where": "Type T section, Alloy Combination Copper/Constantan, Temp. Range (-200 to 370) °C", "source_detail": { "title": "Pyromation: Thermocouple types", "url": "https://www.pyromation.com/products/Thermocouple/Thermocouple-Types.aspx", "kind": "web", "license": "Supplier web page (cited, not reproduced)" } }, { "benchmark": "max_service_temp", "label": "Upper limit of the usable temperature range, Type E pair", "value": 870, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type E, chromel against constantan", "lower_limit": "0 °C", "atmosphere": "continuously oxidising or inert" }, "method": "Upper end of the range printed in the Pyromation thermocouple types table, shown as (0 to 870) °C", "status": "ground", "note": "Upper limit of the pair's Pyromation range, not a single-leg property. The lower limit is in conditions.", "source": "pyromation-types", "where": "Type E section, Alloy Combination Chromel/Constantan, Temp. Range (0 to 870) °C", "source_detail": { "title": "Pyromation: Thermocouple types", "url": "https://www.pyromation.com/products/Thermocouple/Thermocouple-Types.aspx", "kind": "web", "license": "Supplier web page (cited, not reproduced)" } }, { "benchmark": "max_service_temp", "label": "Upper limit of the usable temperature range, Type N pair", "value": 1260, "bound": "exact", "unit": "°C", "scope": "material", "conditions": { "pair": "Type N, Nicrosil against Nisil", "lower_limit": "0 °C", "atmosphere": "air, low oxygen (see Pyromation oxidation note)" }, "method": "Upper end of the range printed in the Pyromation thermocouple types table, shown as (0 to 1260) °C", "status": "ground", "note": "Upper limit of the pair's Pyromation range, not a single-leg property. The lower limit is in conditions.", "source": "pyromation-types", "where": "Type N section, Alloy Combination Nicrosil/Nisil, Temp. Range (0 to 1260) °C", "source_detail": { "title": "Pyromation: Thermocouple types", "url": "https://www.pyromation.com/products/Thermocouple/Thermocouple-Types.aspx", "kind": "web", "license": "Supplier web page (cited, not reproduced)" } } ], "corrosion": [ { "environment": "Moist air or wet storage, iron leg", "headline": "Iron rusts readily, and Isabellenhutte says the copper coating does not protect it.", "effect": "Isabellenhutte says the iron leg has a strong tendency to corrode and rust, and that it should be stored and used in a dry environment. Its note says the copper coating does not act as a rust protection. Kanthal says iron wire is supplied copper-coated to prevent oxidation. No rust rate or test duration is given.", "rating": "severe", "conditions": { "environment": "moist air, wet storage", "basis": "datasheet statements; no test duration stated" }, "source": "isabellen-iron", "where": "Special Remarks on the Alloy; Notes on Treatment" }, { "environment": "Oxidising air above 538 °C, iron leg", "headline": "Iron oxidises rapidly above 538 °C, so heavy gauge wire is recommended.", "effect": "Pyromation says iron oxidises rapidly above 538 °C and that only heavy gauge wire is recommended for high temperature use. The source gives no oxidation rate.", "rating": "severe", "conditions": { "environment": "air, above 538 °C", "basis": "vendor statement; no test duration stated" }, "source": "pyromation-types", "where": "Type J section, oxidation warning sentence" }, { "environment": "Sulphur-bearing atmospheres, iron and Nisil legs", "headline": "Iron and Nisil cannot be exposed to sulphur-containing atmospheres.", "effect": "Kanthal says iron cannot be exposed to sulphur-containing atmospheres, and that Nisil cannot be exposed to sulphur-containing gases. Pyromation says bare Type J elements should not be exposed to sulphurous atmospheres above 538 °C. The sources give no exposure time or concentration.", "rating": "severe", "conditions": { "environment": "sulphur-containing gas", "basis": "vendor statements; no exposure time stated" }, "source": "kanthal-iron", "where": "Special remarks, iron cannot be exposed to sulphur-containing atmospheres; Nisil page, sulphur-containing gases" }, { "environment": "Reducing, vacuum or alternating oxidising and reducing gas, Nicrosil leg", "headline": "Nicrosil cannot be used in reducing or vacuum atmospheres.", "effect": "Kanthal says Nicrosil cannot be exposed to reducing atmospheres, to alternating oxidising and reducing atmospheres, or to vacuum. The Nicrosil wire is for air use. No time to failure is stated.", "rating": "severe", "conditions": { "environment": "reducing gas, vacuum, alternating oxidising and reducing gas", "basis": "vendor statement; no test duration stated" }, "source": "kanthal-nicrosil", "where": "Opening paragraph, cannot be exposed to reducing or alternatively oxidizing and reducing atmospheres or to vacuum" }, { "environment": "Low-oxygen conditions, Type N pair", "headline": "Type N has oxidation stability problems and green rot in some conditions.", "effect": "Pyromation says Type N can replace Type K where Type K has a shorter life, but notes stability problems from oxidation and the development of green rot. Isabellenhutte says Nicrosil and Nisil show higher oxidation stability than the Type K legs because of their silicon and aluminium balance. No corrosion rate is given.", "rating": "moderate", "conditions": { "environment": "low oxygen, Type N pair", "basis": "vendor statements; no test duration stated" }, "source": "pyromation-types", "where": "Type N section, oxidation warning sentence" }, { "environment": "Moist atmosphere, copper and constantan legs", "headline": "Type T is not subject to corrosion in moist atmospheres, according to Pyromation.", "effect": "Pyromation says Type T thermocouples are not subject to corrosion in moist atmospheres. Matthey gives constantan good corrosion resistance and says it can be welded. No corrosion rate is given for either leg.", "rating": "low", "conditions": { "environment": "moist atmosphere", "basis": "vendor statements; no test duration stated" }, "source": "matthey-cuni44", "where": "Main technical properties and features, good corrosion resistance" }, { "environment": "Oxidising or inert air, chromel leg", "headline": "Chromel resists oxidation well enough for bare wire to be used across the range.", "effect": "Concept Alloys says the superior resistance of the alloys to oxidation allows bare metals to be used throughout the useful range of the Chromel/Alumel pair, from -200 °C to 1260 °C. Pyromation says Type E is recommended for continuously oxidising or inert atmospheres. No corrosion rate is given.", "rating": "low", "conditions": { "environment": "oxidising or inert air", "basis": "vendor statements; no test duration stated" }, "source": "concept-chromel", "where": "Opening paragraph, superior resistance of the alloys to oxidation; Pyromation Type E recommended atmospheres" } ], "risks": { "hazards": [ { "text": "Airgas nickel wire and rod SDS: GHS Hazard Classification is Not Classified, with no symbol or signal word. The sheet covers a nickel wire and rod product, not a thermocouple pair.", "ghs": [], "source": "airgas-nickel-sds", "where": "Section 2, GHS Hazard Classification line" }, { "text": "The same SDS lists manganese, nickel, chromium, chromium oxide, silicon and copper among its ingredients, with exposure limits for several of them.", "ghs": [], "source": "airgas-nickel-sds", "where": "Section 2 ingredient list and the exposure limits table" } ], "failure_risks": [ { "mode": "Rust of the iron leg in moist or wet storage", "trigger": "Moist air or wet storage of bare or copper-coated iron wire", "consequence": "Isabellenhutte says the iron leg has a strong tendency to corrode and rust. The source gives no rate and no effect on calibration.", "severity": "high", "source": "isabellen-iron", "where": "Special Remarks on the Alloy" }, { "mode": "Attack by sulphur on the iron and Nisil legs", "trigger": "Exposure of the iron or Nisil leg to sulphur-containing gas", "consequence": "Kanthal says the leg cannot be exposed to sulphur-containing gases, and Pyromation says bare Type J elements should not be exposed to sulphurous atmospheres above 538 °C. No failure time is given.", "severity": "high", "source": "kanthal-iron", "where": "Opening statement on sulphur-containing atmospheres" }, { "mode": "Use of Nicrosil in vacuum or reducing gas", "trigger": "Vacuum, reducing atmosphere or alternating oxidising and reducing gas", "consequence": "Kanthal says the sheet cannot be exposed to these atmospheres. The source gives no failure time.", "severity": "high", "source": "kanthal-nicrosil", "where": "Opening paragraph, cannot be exposed to reducing or alternatively oxidizing and reducing atmospheres or to vacuum" }, { "mode": "Green rot and oxidation of the Type N pair", "trigger": "Oxidation and low-oxygen conditions at high temperature", "consequence": "Pyromation reports stability problems from oxidation and the development of green rot. No drift value is given.", "severity": "moderate", "source": "pyromation-types", "where": "Type N section, oxidation warning sentence" }, { "mode": "Rapid oxidation of bare iron above 538 °C", "trigger": "Bare iron wire in air above 538 °C", "consequence": "Pyromation says iron oxidises rapidly above 538 °C and recommends heavy gauge wire. No rate is given.", "severity": "moderate", "source": "pyromation-types", "where": "Type J section, oxidation warning sentence" } ], "side_effects": [ { "text": "The Airgas SDS says welding fumes can affect the eyes, skin and respiratory system, and lists pancreas and liver effects, from the fume produced when welding nickel-base wire.", "affects": "Handling of fume from grinding or welding nickel-containing legs", "source": "airgas-nickel-sds", "where": "Section 2, Hazards line on welding fumes and gases" } ], "handling": [ { "text": "Keep the iron leg dry and store it in a dry environment (Isabellenhutte).", "source": "isabellen-iron", "where": "Special Remarks on the Alloy" }, { "text": "Keep iron and Nisil away from sulphur-containing gas (Kanthal).", "source": "kanthal-iron", "where": "Opening statement on sulphur-containing atmospheres" }, { "text": "Keep the iron leg above zero degrees C; Kanthal says iron cannot be exposed to temperatures below zero.", "source": "kanthal-iron", "where": "Opening statement on temperatures below zero" }, { "text": "Keep Nicrosil out of vacuum and reducing gas (Kanthal).", "source": "kanthal-nicrosil", "where": "Opening paragraph" } ], "mitigations": [] }, "uses": [ { "application": "thermal-control", "device": "Type N thermocouple, Nicrosil and Nisil", "example": "Isabellenhutte's Type N sheet lists use in exhaust systems, turbochargers, casts, furnaces and nuclear power stations.", "source": "isabellen-typeN", "where": "Application notes table" }, { "application": "thermal-control", "device": "Type J thermocouple, iron and constantan", "example": "Pyromation says Type J suits vacuum, reducing or inert atmospheres, and oxidising atmosphere with reduced life, and that iron oxidises rapidly above 538 °C.", "source": "pyromation-types", "where": "Type J section, use and atmospheres" }, { "application": "thermal-control", "device": "Type T thermocouple, copper and constantan", "example": "Pyromation says Type T works in oxidising, reducing or inert atmospheres, and in vacuum, and that it is not subject to corrosion in moist atmospheres.", "source": "pyromation-types", "where": "Type T section, use and corrosion sentences" } ], "supply": [ { "subject": "Iron", "producers": [ { "country": "China", "share_percent": 63.8, "year": 2025 }, { "country": "India", "share_percent": 7.5, "year": 2025 }, { "country": "Japan", "share_percent": 4.5, "year": 2025 }, { "country": "Russia", "share_percent": 3.6, "year": 2025 } ], "critical_lists": [ { "list": "USGS 2025 List of Critical Minerals", "listed": false } ], "recycling": "USGS iron and steel chapter: recycling is covered in the Iron and Steel Scrap chapter, which is not read in this run.", "substitutes": [ "USGS: iron and steel compete with lighter materials such as aluminum and plastics in the automotive industry." ], "source": "usgs-iron-steel", "where": "World Production table, pig iron 2025e (world total 1,300 million t, rounded; shares calculated by Space Mushroom against that total); Substitutes; the USGS 2025 list has no iron entry (see usgs-critical-2025)" }, { "subject": "Copper", "producers": [ { "country": "Chile", "share_percent": 23, "year": 2025 }, { "country": "Congo (Kinshasa)", "share_percent": 13.9, "year": 2025 }, { "country": "Peru", "share_percent": 11.7, "year": 2025 }, { "country": "China", "share_percent": 7.8, "year": 2025 } ], "critical_lists": [ { "list": "USGS 2025 List of Critical Minerals", "listed": true } ], "recycling": "USGS: copper recovered from scrap contributed about 30 % of the U.S. copper supply in 2025.", "substitutes": [ "USGS: aluminum substitutes for copper in radiators, tube, electrical equipment and power cable; titanium and steel are used in heat exchangers." ], "source": "usgs-copper", "where": "World Mine Production and Reserves table, 2025e (world total 23,000 thousand t, rounded; shares calculated by Space Mushroom against that total); Recycling; Substitutes; the 2025 list adds copper" }, { "subject": "Nickel", "producers": [ { "country": "Indonesia", "share_percent": 66.7, "year": 2025 }, { "country": "Philippines", "share_percent": 6.9, "year": 2025 }, { "country": "Russia", "share_percent": 5.1, "year": 2025 }, { "country": "Canada", "share_percent": 3.6, "year": 2025 } ], "critical_lists": [ { "list": "USGS 2025 List of Critical Minerals", "listed": true } ], "recycling": "USGS: most secondary nickel is the nickel content of stainless-steel scrap; nickel recovered from scrap was about 60 % of apparent consumption in 2025.", "substitutes": [ "USGS: low-nickel, duplex or ultrahigh-chromium stainless steels can replace austenitic grades; titanium alloys can substitute for nickel-base alloys in corrosive environments." ], "source": "usgs-nickel", "where": "World Mine Production and Reserves table, 2025e (world total 3,900,000 t; shares calculated by Space Mushroom against that total); Recycling; Substitutes" }, { "subject": "Chromium", "producers": [ { "country": "South Africa", "share_percent": 45.1, "year": 2025 }, { "country": "Turkey", "share_percent": 17.6, "year": 2025 }, { "country": "Kazakhstan", "share_percent": 13.7, "year": 2025 }, { "country": "India", "share_percent": 5.9, "year": 2025 } ], "critical_lists": [ { "list": "USGS 2025 List of Critical Minerals", "listed": true } ], "recycling": "USGS: recycled chromium in stainless-steel scrap accounted for 21 % of apparent consumption in 2025.", "substitutes": [ "USGS: chromium has no substitute in stainless steel, the leading end use, or in superalloys." ], "source": "usgs-chromium", "where": "World Mine Production and Reserves table, 2025e (world total 51,000 thousand t, rounded; shares calculated by Space Mushroom against that total); Recycling; Substitutes" } ], "media": [], "documents": [ { "title": "Kanthal: Nicrosil thermocouple wire datasheet (updated 2024-09-05)", "type": "datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nicrosil/", "year": 2024 }, { "title": "Kanthal: Nisil thermocouple wire datasheet (updated 2021-02-04)", "type": "datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nisil/", "year": 2021 }, { "title": "Kanthal: thermocouple iron datasheet (updated 2021-02-04)", "type": "datasheet", "url": "https://www.kanthal.com/en/products/material-datasheets/wire/thermocouple-wire/thermocouple-iron" }, { "title": "Isabellenhutte: NISIL data sheet (issue 17-April-2019)", "type": "datasheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/NISIL.pdf", "year": 2019 }, { "title": "Isabellenhutte: Thermocouples type N / extension leads type NX data sheet (issue 27-March-2020)", "type": "datasheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/Thermocouples%20type%20N_NX.pdf", "year": 2020 }, { "title": "Isabellenhutte: IRON data sheet (issue 30-September-2022)", "type": "datasheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/IRON.pdf", "year": 2022 }, { "title": "Concept Alloys: Chromel-P technical data sheet (Rev. 12-23-09)", "type": "datasheet", "url": "https://conceptalloys.com/wp-content/uploads/2013/10/Chromel-PGMVdatasheet091223.pdf", "year": 2009 }, { "title": "Matthey: CuNi44Mn1 constantan technical data sheet", "type": "datasheet", "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/CuNi44Mn1_v22E.pdf" }, { "title": "Aurubis: Technical datasheet C10200 (Cu-OF)", "type": "datasheet", "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf" }, { "title": "Pelican Wire: Thermocouple tolerances (ASTM E230 table)", "type": "database", "url": "https://pelicanwire.com/resources/thermocouple-wire-resources/thermocouple-tolerances/" }, { "title": "Pyromation: Thermocouple types", "type": "datasheet", "url": "https://www.pyromation.com/products/Thermocouple/Thermocouple-Types.aspx" }, { "title": "USGS Mineral Commodity Summaries 2026: Iron and Steel", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-steel.pdf", "year": 2026 }, { "title": "USGS Mineral Commodity Summaries 2026: Copper", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf", "year": 2026 }, { "title": "USGS Mineral Commodity Summaries 2026: Nickel", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf", "year": 2026 }, { "title": "USGS Mineral Commodity Summaries 2026: Chromium", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf", "year": 2026 }, { "title": "USGS: About the 2025 List of Critical Minerals", "type": "report", "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals", "year": 2025 }, { "title": "Airgas: Nickel Wire and Rod safety data sheet (approval 2-1-2016)", "type": "sds", "url": "https://www.airgas.com/msds/005727.pdf", "year": 2016 } ], "gaps": [ "IEC 60584 classes for Types J, T and E are not stored. The Rangdong tolerance chart refused connection in this run, and the search snippets were not used. Only the Type N IEC Class 1 value is stored, from the Isabellenhutte sheet.", "The iron leg has two melting points (1535 °C from Kanthal and 1496 °C from Isabellenhutte), and two densities (7.86 and 7.874 g/cm3). Both are kept. The purity of each product is not stated, and the Kanthal page says the material is magnetic.", "Nicrosil and Nisil also differ between Kanthal and Isabellenhutte. Nicrosil density is 8.53 against 8.50 g/cm3, Nicrosil melting point 1420 against 1394 °C, Nisil melting point 1420 against 1341 °C, and the composition is Cr 14.2 against 14.6 % and Si 1.5 against 1.30 %. Every value is kept with its source.", "The copper leg is a proxy. Aurubis C10200 is commercial oxygen-free copper with 99.95 % minimum Cu, not a thermocouple-grade copper datasheet. A datasheet for the Type T positive leg was not read in this run.", "The chromel sheet is for Chromel-P, labelled ANSI KP, with nominal 90 Ni and 10 Cr. Its use as the Type E positive leg is not confirmed by a Type E source read in this run.", "No corrosion rate, oxidation weight gain, drift per hour or test duration was found for any of the four pairs. The corrosion entries are qualitative statements from datasheets and the Pyromation pages.", "Designations (UNS, EN and DIN codes) are not stored in this file, because a designation belongs to one grade. The constantan leg has UNS C72150 and EN 2.0842 in the Matthey sheet, and they belong in constantan.yaml.", "The Type J and Type E output in microvolts per degree was not stored, because no datasheet read in this run gives it.", "The iron Curie or magnetic transition temperatures were not read in a fetched page. Only a search snippet gave 770 °C and 900 °C, so they are not stored.", "Hazard data rest on one SDS, the Airgas nickel wire and rod sheet, which covers a nickel product. No SDS was read for iron, copper, constantan or chromel thermocouple wire, and PubChem was not read.", "Supply shares for iron are calculated against the rounded world pig iron total of 1,300 million t, and the USGS iron chapter read here gives pig iron, not iron ore. The EU critical raw materials list was not checked for any of the four metals.", "Non-canonical benchmark names are used for limit_of_error, thermoelectric_emf and temperature_coefficient_of_resistance. They are listed in the property notes so the import can map them." ], "story": { "why": "A thermocouple pair is two dissimilar wires joined at a hot junction, and the voltage across the cold ends gives the temperature. This profile covers four base-metal pairs. Type J uses iron against constantan, Type T uses copper against constantan, Type E uses chromel against constantan, and Type N uses Nicrosil against Nisil. The pairs are chosen by atmosphere more than by range, because the legs fail differently in air, moisture, sulphur and vacuum.", "uses": [ { "where": "Type N in furnaces and exhaust systems", "line": "Isabellenhutte lists Type N use in exhaust systems, turbochargers, casts, furnaces and nuclear power stations." }, { "where": "Type J in vacuum or reducing gas", "line": "Pyromation says Type J suits vacuum, reducing or inert atmospheres, and oxidising atmosphere with reduced life." }, { "where": "Type T in moist or vacuum service", "line": "Pyromation says Type T works in oxidising, reducing or inert atmospheres and in vacuum, and is not subject to corrosion in moist atmospheres." } ], "can_do": [ { "label": "Stay within a standard limit", "line": "Pelican gives the Type J standard limit as 2.2 °C or 0.75 %, over 0 to 760 °C (ASTM E230).", "benchmark": "limit_of_error", "scope": "material", "value": "2.2 °C standard limit for Type J" }, { "label": "Hot in air, Type N", "line": "Kanthal gives 1100 °C as the guide maximum continuous temperature for 3.26 mm bare Nicrosil and Nisil wire.", "benchmark": "max_service_temp", "scope": "material", "value": "1100 °C bare wire" }, { "label": "Stable resistance, constantan", "line": "Matthey gives constantan a temperature coefficient of electrical resistance of -80 to +40 10-6/K over 20 to 105 °C.", "benchmark": "temperature_coefficient_of_resistance", "scope": "material", "value": "-80 to 40 10-6/K" } ], "compare": "Compared on the same benchmarks, the copper leg melts at 1083 °C, the constantan leg at 1230 to 1290 °C (Matthey), chromel at 1427 °C (Concept Alloys), and the Nicrosil and Nisil legs at 1420 °C each in the Kanthal sheets. These are leg values, not a ranking of the pairs.", "compare_rows": [ { "label": "Density", "benchmark": "density", "scope": "material" }, { "label": "Melting point", "benchmark": "melting_point", "scope": "material" }, { "label": "Electrical resistivity", "benchmark": "electrical_resistivity", "scope": "material" } ], "handling": [ "Keep the iron leg dry and out of sulphur-containing gas (Isabellenhutte and Kanthal).", "Keep Nicrosil out of vacuum and reducing gas (Kanthal).", "Keep bare Nicrosil and Nisil wire at or below the guide values in the Kanthal table (1100 °C at 3.26 mm)." ], "good_for": [ "Type N in air at high temperature, with a guide maximum of 1100 °C for 3.26 mm bare Nicrosil and Nisil wire (Kanthal) and standard limit of error 2.2 °C (ASTM E230).", "Type T in moist air and in vacuum, with copper and constantan legs (Pyromation).", "Type E in continuously oxidising or inert atmospheres (Pyromation), with a pair range of 0 to 870 °C." ], "watch_out": [ "Iron rusts readily, and the copper coating does not protect it (Isabellenhutte).", "Iron and Nisil cannot be exposed to sulphur-containing gas (Kanthal).", "Nicrosil cannot be used in vacuum or reducing gas (Kanthal).", "The iron melting point differs by 39 °C between Kanthal and Isabellenhutte, and the Nisil melting point differs by 79 °C." ], "verdict": "The four pairs cover base-metal sensing, and each pair is limited by its atmosphere. Type N suits high temperature in air, Type T suits moist air and low temperature, Type J needs dry and sulphur-free service, and Type E suits oxidising or inert air. The sources give tolerance and range figures, but no corrosion rates or drift data for any pair.", "recipe": { "line": "Thermocouple wire is a pair of legs, not one alloy. The four pairs are iron against constantan (Type J), copper against constantan (Type T), chromel against constantan (Type E) and Nicrosil against Nisil (Type N). Constantan is a copper-nickel alloy with manganese (Matthey CuNi44Mn1). Iron, copper and chromel are supplied as wire, and Nicrosil and Nisil as wire, strip or rod (Kanthal, Isabellenhutte).", "parts": [ { "name": "Iron", "symbol": "Fe", "role": "Positive leg of Type J." }, { "name": "Copper", "symbol": "Cu", "role": "Positive leg of Type T, and the base of constantan." }, { "name": "Nickel", "symbol": "Ni", "role": "Base of the chromel, Nicrosil and Nisil legs, and the nickel content of constantan." }, { "name": "Chromium", "symbol": "Cr", "role": "Gives the chromel and Nicrosil legs their high-temperature stability in air." }, { "name": "Silicon", "symbol": "Si", "role": "Gives Nicrosil and Nisil their thermoelectric stability and oxidation resistance." }, { "name": "Manganese", "symbol": "Mn", "role": "Minor addition to constantan, the negative leg of Types J, T and E." } ] }, "risk_groups": [ { "title": "For people", "lead": "The four pairs are alloys of iron, copper, nickel and chromium. The only hazard source read is the Airgas nickel wire and rod SDS, which is Not Classified under GHS.", "points": [ { "label": "Supplier classification", "line": "The Airgas nickel wire and rod SDS is classified as Not Classified under GHS and has no signal word. It covers a nickel wire and rod product, not a thermocouple pair." }, { "label": "Fume", "line": "The same SDS lists manganese, nickel, chromium and silicon among its ingredients, so grinding or welding these legs can produce fume with those metals." } ], "level": 1, "verdict": "No pair-level hazard classification found" }, { "title": "If it fails", "lead": "The failure routes in the sources are atmosphere, moisture and temperature. The sources give limits but no failure rates for any pair.", "points": [ { "label": "Rust", "line": "Isabellenhutte says the iron leg has a strong tendency to rust and should be stored dry." }, { "label": "Sulphur", "line": "Kanthal says the iron and Nisil legs cannot be exposed to sulphur-containing gas." }, { "label": "Vacuum and reducing gas", "line": "Kanthal says Nicrosil cannot be used in vacuum or reducing gas." } ] }, { "title": "Handling and storage", "points": [ { "label": "Keep iron dry", "line": "Store the iron leg in a dry environment, as Isabellenhutte says." }, { "label": "Keep it above zero", "line": "Kanthal says the iron leg cannot be exposed to temperatures below zero." } ] } ] }, "updated": "2026-10-26", "review": { "status": "draft", "method": "assistant", "checked_values": 61, "unreachable": 1, "caveats": 5, "note": "Values were read by an AI assistant on 2026-10-26 from the pages and PDFs named in each entry. Unreachable in this run: the Rangdong IEC 60584 tolerance chart (connection refused), so IEC classes for Types J, T and E are not stored, and the Kanthal iron page was read through a fetch tool, not the browser. Caveats: the copper leg is a commercial oxygen-free copper proxy; the iron and Nicrosil/Nisil values disagree between Kanthal and Isabellenhutte, and both are kept; Chromel-P is labelled KP and is used as the Type E positive leg without a Type E source; supply shares are calculated against rounded world totals." }, "sources": { "kanthal-nicrosil": { "title": "Kanthal: Nicrosil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nicrosil/", "year": 2024, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" }, "kanthal-nisil": { "title": "Kanthal: Nisil thermocouple wire datasheet", "url": "https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/thermocouple-wire/nisil/", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" }, "kanthal-iron": { "title": "Kanthal: thermocouple iron datasheet", "url": "https://www.kanthal.com/en/products/material-datasheets/wire/thermocouple-wire/thermocouple-iron", "year": 2021, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" }, "isabellen-nisil": { "title": "Isabellenhutte: NISIL data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/NISIL.pdf", "year": 2019, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" }, "isabellen-typeN": { "title": "Isabellenhutte: Thermocouples type N / extension leads type NX", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/Thermocouples%20type%20N_NX.pdf", "year": 2020, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" }, "isabellen-iron": { "title": "Isabellenhutte: IRON data sheet", "url": "https://www.isabellenhuette.com/hubfs/Files/Data-sheets/LE/Thermo/IRON.pdf", "year": 2022, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" }, "concept-chromel": { "title": "Concept Alloys: Chromel-P technical data sheet", "url": "https://conceptalloys.com/wp-content/uploads/2013/10/Chromel-PGMVdatasheet091223.pdf", "year": 2009, "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" }, "matthey-cuni44": { "title": "Matthey: CuNi44Mn1 constantan technical data sheet", "url": "https://www.matthey.ch/fileadmin/user_upload/downloads/fichetechnique/EN/CuNi44Mn1_v22E.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" }, "aurubis-c10200": { "title": "Aurubis: Technical datasheet C10200 (Cu-OF)", "url": "https://www.aurubis.be/en/dam/jcr:90029b00-b968-486e-bde0-ce56f16022cd/c10200-cu-of-us.pdf", "kind": "datasheet", "license": "Manufacturer datasheet (cited, not reproduced)" }, "pelican-tolerances": { "title": "Pelican Wire: Thermocouple tolerances", "url": "https://pelicanwire.com/resources/thermocouple-wire-resources/thermocouple-tolerances/", "kind": "web", "license": "Supplier web page (cited, not reproduced)" }, "pyromation-types": { "title": "Pyromation: Thermocouple types", "url": "https://www.pyromation.com/products/Thermocouple/Thermocouple-Types.aspx", "kind": "web", "license": "Supplier web page (cited, not reproduced)" }, "usgs-iron-steel": { "title": "Mineral Commodity Summaries 2026, Iron and Steel", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-steel.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "usgs-copper": { "title": "Mineral Commodity Summaries 2026, Copper", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "usgs-nickel": { "title": "Mineral Commodity Summaries 2026, Nickel", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "usgs-chromium": { "title": "Mineral Commodity Summaries 2026, Chromium", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "usgs-critical-2025": { "title": "USGS: About the 2025 List of Critical Minerals", "url": "https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals", "year": 2025, "kind": "report", "license": "public domain (USGS)" }, "airgas-nickel-sds": { "title": "Safety Data Sheet, Nickel Wire and Rod (Airgas)", "url": "https://www.airgas.com/msds/005727.pdf", "year": 2016, "kind": "datasheet", "license": "Supplier safety data sheet (cited, not reproduced)" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/thermocouple-alloys/" }