Thermocouple engineering tools and reference tables
Free calculators and lookup tables for Type K EMF conversion, colour codes, tolerance, atmospheric compatibility, junction selection, gauge response and conductor resistance: every figure drawn from the same verified reference data we manufacture to.
These tools exist for the same reason our technical pages do: to give you a number you can act on. Each one either calculates from a verified reference set or filters a table we actually publish, and each says plainly which one it is doing. Nothing here is a placeholder waiting to be filled in.
Converters
Type K millivolt to temperature converter
Convert a Type K reading in millivolts to °C, showing which two of the 17 verified reference points the answer sits between.
Type K temperature to millivolt converter
Convert a Type K process temperature in °C to the expected EMF in millivolts at a 0 °C reference junction.
AWG to mm² and AWG to mm converter
Convert AWG gauge numbers to millimetre diameter and square-millimetre cross-section using the standard AWG geometric definition.
Reference tables
Type K thermocouple EMF reference table
The full Type K EMF reference table from −200 °C to +1370 °C at a 0 °C reference junction, with a one-click CSV export.
Thermocouple colour codes (ANSI and IEC)
Colour code, polarity and swatch for Type K, J, T, E, N, R, S and B to ANSI MC96.1 and IEC 60584-3.
Maximum temperature by thermocouple alloy
Operating range and tolerance side by side for all eight standardised thermocouple types, from Type T to Type B.
Selection aids
Thermocouple atmosphere compatibility
Filter the eight standardised types by oxidising, reducing, vacuum or moist service to see which alloys are recommended and which to avoid.
Thermocouple junction style selector
Decide between exposed, grounded and ungrounded junctions from response speed and electrical isolation requirements.
Thermocouple tolerance by alloy
Look up the supplied tolerance band for each standardised type against its verified operating range.
Calculation aids
Thermocouple loop uncertainty budget
Combine wire tolerance, cold-junction error, extension-junction error, drift and shield noise into one loop uncertainty figure.
Thermocouple response time by gauge
Estimate step response at any stocked gauge from the verified φ0.5 mm baseline, using the diameter-squared scaling the stock is drawn to.
Thermocouple wire resistance per metre
Estimate conductor resistance per metre at any diameter from three verified Type K set points, and check it against a planned run length.
How to read these tools honestly
- Interpolated, not fitted. Temperature and millivolt conversions are linearly interpolated between the published reference points. Each result tells you which two points it sits between, so you can judge the interval yourself instead of trusting a hidden curve.
- Scaled from a verified baseline. Response time and resistance per metre are calculated from measured set points using the physical scaling the stock is drawn to, not from a per-gauge lookup we have not verified.
- Out of range means no answer. If an input falls outside the verified table, the tool returns nothing rather than extrapolating a plausible-looking figure.
Frequently Asked Questions (FAQ)
Are these thermocouple tools free to use?
Yes. Every calculator and lookup table on this page is free, needs no account, and runs entirely in your browser, no reading you type is sent anywhere.
Where do the numbers in the tools come from?
From our own verified alloy datasheets and the governing standards we work to: IEC 60584-1 / ASTM E230 for EMF and tolerances, and the NIST ITS-90 reference tables. Where a figure is not verified in-house we say so rather than guess.
Why is there no calculator for every thermocouple type?
Because only Type K has a complete verified millivolt table in our own reference data. Publishing a Type J, T or E converter without that table would mean inventing numbers, so those types are supplied with a batch EMF certificate instead.
Can I use the tools offline?
The pages are static and the calculations run in the browser, so once a page has loaded it keeps working without a connection. The Type K reference table also exports to CSV for use in your own spreadsheet.
Need the wire behind the number?
Send the alloy, diameter and accuracy class you need, we quote against a furnace batch with a traceable EMF certificate.