Datasets:

referencesource
/

thermocouple-type-color-code-crosswalk

also_reported listlengths 4 6 ⌀	ansi_extension_jacket stringclasses 8 values	ansi_negative_color stringclasses 1 value	ansi_positive_color stringclasses 8 values	citation stringclasses 2 values	disagreements listlengths 0 0 ⌀	id stringlengths 1 1	negative_conductor stringclasses 6 values	positive_conductor stringclasses 8 values	source stringclasses 2 values	source_quote stringlengths 161 854	thermocouple_type stringlengths 1 1	url stringlengths 69 69	verified_fields listlengths 2 7	temperature_range stringclasses 1 value
[ { "as_of": "2026-08-19T00:00:00", "field": "temperature_range", "source": "https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf", "source_quote": "B B Do Not Insert in Metal NONE – PLATINUM- Platinum- Tubes. Beware of – – Contamination...	Gray	Red	Gray	ANSI/ASTM Thermocouple Color Codes	[]	b	Platinum 6% rhodium	Platinum 30% rhodium	https://thermometricscorp.com/thermocouple-color-codes.html	Type \| Positive conductor \| Negative conductor \| Positive color \| Negative color \| Extension-grade jacket \| Thermocouple-grade jacket shown in legacy assets \| T \| Copper \| Constantan \| Blue \| Red \| Blue \| Brown \| J \| Iron \| Constantan \| White \| Red \| Black \| Brown \| E \| Chromel \| Constantan \| Purple \| Red \| Purple \| Br...	B	https://referencesource.org/thermocouple-type-color-code-crosswalk/b/	[ "ansi_extension_jacket", "ansi_negative_color", "ansi_positive_color", "citation", "negative_conductor", "positive_conductor", "thermocouple_type" ]	null
[ { "as_of": "2026-08-19T00:00:00", "field": "temperature_range", "source": "https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf", "source_quote": "C* C Vacuum, Inert, Hydrogen. NONE + TUNGSTEN- TUNGSTEN- Beware of Embrittlement. NO STA...	Red	Red	Green	ANSI/ASTM Thermocouple Color Codes	[]	c	Tungsten 26% rhenium	Tungsten 5% rhenium	https://thermometricscorp.com/thermocouple-color-codes.html	Type \| Positive conductor \| Negative conductor \| Positive color \| Negative color \| Extension-grade jacket \| Thermocouple-grade jacket shown in legacy assets \| T \| Copper \| Constantan \| Blue \| Red \| Blue \| Brown \| J \| Iron \| Constantan \| White \| Red \| Black \| Brown \| E \| Chromel \| Constantan \| Purple \| Red \| Purple \| Br...	C	https://referencesource.org/thermocouple-type-color-code-crosswalk/c/	[ "ansi_extension_jacket", "ansi_negative_color", "ansi_positive_color", "citation", "negative_conductor", "positive_conductor", "thermocouple_type" ]	null
null	null	null	null	ANSI and IEC Color Codes	null	d	null	null	https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf	D* D Vacuum, Inert, Hydrogen. + TUNGSTEN- TUNGSTEN- Beware of Embrittlement. Not Practical Below NO STANDARD NONE 0 to 2320°C USE ANSI – 3% RHENIUM 25% RHENIUM 399°C (750°F)–Not for ESTABLISHED W-3% Re W-25% Re 32 to 4208°F 0 to 39.506 COLOR CODE (W3) Oxidizing Atmosphere (W3)	D	https://referencesource.org/thermocouple-type-color-code-crosswalk/d/	[ "citation", "temperature_range", "thermocouple_type" ]	0 to 2320°C
[ { "as_of": "2026-08-19T00:00:00", "field": "temperature_range", "source": "https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf", "source_quote": "CHROMEGA® Oxidizing or Inert. + + E E CONSTANTAN Limited Use in Vacuum or –270 to 1000°C...	Purple	Red	Purple	ANSI/ASTM Thermocouple Color Codes	[]	e	Constantan	Chromel	https://thermometricscorp.com/thermocouple-color-codes.html	Type \| Positive conductor \| Negative conductor \| Positive color \| Negative color \| Extension-grade jacket \| Thermocouple-grade jacket shown in legacy assets \| T \| Copper \| Constantan \| Blue \| Red \| Blue \| Brown \| J \| Iron \| Constantan \| White \| Red \| Black \| Brown \| E \| Chromel \| Constantan \| Purple \| Red \| Purple \| Br...	E	https://referencesource.org/thermocouple-type-color-code-crosswalk/e/	[ "ansi_extension_jacket", "ansi_negative_color", "ansi_positive_color", "citation", "negative_conductor", "positive_conductor", "thermocouple_type" ]	null
null	null	null	null	ANSI and IEC Color Codes	null	g	null	null	https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf	G* Vacuum, Inert, Hydrogen. NONE ESTABLISHED + – TUNGSTEN W TUNGSTEN- 26% RHENIUM Beware of Embrittlement. Not Practical Below 399°C (750°F). 0 to 2320°C 0 to 38.564 NO STANDARD USE ANSI COLOR CODE G (W) W-26% Re Not for Oxidizing Atmosphere 32 to 4208°F (W)	G	https://referencesource.org/thermocouple-type-color-code-crosswalk/g/	[ "citation", "temperature_range", "thermocouple_type" ]	0 to 2320°C
[ { "as_of": "2026-08-19T00:00:00", "field": "temperature_range", "source": "https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf", "source_quote": "J J IRON CONSTANTAN – Fe COPPER- in Oxidizing at High – – Temperatures. –210 to 1200°C –...	Black	Red	White	ANSI/ASTM Thermocouple Color Codes	[]	j	Constantan	Iron	https://thermometricscorp.com/thermocouple-color-codes.html	Type \| Positive conductor \| Negative conductor \| Positive color \| Negative color \| Extension-grade jacket \| Thermocouple-grade jacket shown in legacy assets \| T \| Copper \| Constantan \| Blue \| Red \| Blue \| Brown \| J \| Iron \| Constantan \| White \| Red \| Black \| Brown \|	J	https://referencesource.org/thermocouple-type-color-code-crosswalk/j/	[ "ansi_extension_jacket", "ansi_negative_color", "ansi_positive_color", "citation", "negative_conductor", "positive_conductor", "thermocouple_type" ]	null
[ { "as_of": "2026-08-19T00:00:00", "field": "temperature_range", "source": "https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf", "source_quote": "ALOMEGA ® Clean Oxidizing and Inert. + + CHROMEGA ® + + K K Limited Use in Vacuum NICKEL...	Yellow	Red	Yellow	ANSI/ASTM Thermocouple Color Codes	[]	k	Alumel	Chromel	https://thermometricscorp.com/thermocouple-color-codes.html	Type \| Positive conductor \| Negative conductor \| Positive color \| Negative color \| Extension-grade jacket \| Thermocouple-grade jacket shown in legacy assets \| T \| Copper \| Constantan \| Blue \| Red \| Blue \| Brown \| J \| Iron \| Constantan \| White \| Red \| Black \| Brown \| E \| Chromel \| Constantan \| Purple \| Red \| Purple \| Br...	K	https://referencesource.org/thermocouple-type-color-code-crosswalk/k/	[ "ansi_extension_jacket", "ansi_negative_color", "ansi_positive_color", "citation", "negative_conductor", "positive_conductor", "thermocouple_type" ]	null
[ { "as_of": "2026-08-19T00:00:00", "field": "temperature_range", "source": "https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf", "source_quote": "Alternative + + N N OMEGA-P® OMEGA-N® to Type K. –270 to 1300°C –4.345 – – NICROSIL – – ...	Orange	Red	Orange	ANSI/ASTM Thermocouple Color Codes	[]	n	Nisil	Nicrosil	https://thermometricscorp.com/thermocouple-color-codes.html	Type \| Positive conductor \| Negative conductor \| Positive color \| Negative color \| Extension-grade jacket \| Thermocouple-grade jacket shown in legacy assets \| T \| Copper \| Constantan \| Blue \| Red \| Blue \| Brown \| J \| Iron \| Constantan \| White \| Red \| Black \| Brown \| E \| Chromel \| Constantan \| Purple \| Red \| Purple \| Br...	N	https://referencesource.org/thermocouple-type-color-code-crosswalk/n/	[ "ansi_extension_jacket", "ansi_negative_color", "ansi_positive_color", "citation", "negative_conductor", "positive_conductor", "thermocouple_type" ]	null
[ { "as_of": "2026-08-19T00:00:00", "field": "temperature_range", "source": "https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf", "source_quote": "R R Do Not Insert in Metal NONE PLATINUM- Platinum Tubes. Beware of –50 to 1768°C –0.226...	Green	Red	Black	ANSI/ASTM Thermocouple Color Codes	[]	r	Pure platinum	Platinum 13% rhodium	https://thermometricscorp.com/thermocouple-color-codes.html	Type \| Positive conductor \| Negative conductor \| Positive color \| Negative color \| Extension-grade jacket \| Thermocouple-grade jacket shown in legacy assets \| T \| Copper \| Constantan \| Blue \| Red \| Blue \| Brown \| J \| Iron \| Constantan \| White \| Red \| Black \| Brown \| E \| Chromel \| Constantan \| Purple \| Red \| Purple \| Br...	R	https://referencesource.org/thermocouple-type-color-code-crosswalk/r/	[ "ansi_extension_jacket", "ansi_negative_color", "ansi_positive_color", "citation", "negative_conductor", "positive_conductor", "thermocouple_type" ]	null
[ { "as_of": "2026-08-19T00:00:00", "field": "temperature_range", "source": "https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf", "source_quote": "S S Do Not Insert in Metal NONE PLATINUM- Platinum Tubes. Beware of – 10% RHODIUM –50 to...	Green	Red	Black	ANSI/ASTM Thermocouple Color Codes	[]	s	Pure platinum	Platinum 10% rhodium	https://thermometricscorp.com/thermocouple-color-codes.html	Type \| Positive conductor \| Negative conductor \| Positive color \| Negative color \| Extension-grade jacket \| Thermocouple-grade jacket shown in legacy assets \| T \| Copper \| Constantan \| Blue \| Red \| Blue \| Brown \| J \| Iron \| Constantan \| White \| Red \| Black \| Brown \| E \| Chromel \| Constantan \| Purple \| Red \| Purple \| Br...	S	https://referencesource.org/thermocouple-type-color-code-crosswalk/s/	[ "ansi_extension_jacket", "ansi_negative_color", "ansi_positive_color", "citation", "negative_conductor", "positive_conductor", "thermocouple_type" ]	null
[ { "as_of": "2026-08-19T00:00:00", "field": "temperature_range", "source": "https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf", "source_quote": "Mild Oxidizing, + + + + T T CONSTANTAN Reducing Vacuum or – – COPPER COPPER- Inert. Good...	Blue	Red	Blue	ANSI/ASTM Thermocouple Color Codes	[]	t	Constantan	Copper	https://thermometricscorp.com/thermocouple-color-codes.html	Type \| Positive conductor \| Negative conductor \| Positive color \| Negative color \| Extension-grade jacket \| Thermocouple-grade jacket shown in legacy assets \| T \| Copper \| Constantan \| Blue \| Red \| Blue \| Brown \|	T	https://referencesource.org/thermocouple-type-color-code-crosswalk/t/	[ "ansi_extension_jacket", "ansi_negative_color", "ansi_positive_color", "citation", "negative_conductor", "positive_conductor", "thermocouple_type" ]	null
null	null	null	null	ANSI and IEC Color Codes	null	u	null	null	https://assets.omega.com/pdf/test-and-measurement-equipment/temperature/sensors/thermocouple-probes/tc_colorcodes.pdf	Extension Grade + + + U U NONE COPPER-LOW Connecting Wire for ESTABLISHED – COPPER R & S Thermocouples, – – Cu NICKEL Also Known as RX & SX Cu-Ni Extension Wire.	U	https://referencesource.org/thermocouple-type-color-code-crosswalk/u/	[ "citation", "thermocouple_type" ]	null

Thermocouple type letter to alloy pair, ANSI/IEC color code and tolerance class

Canonical, always-current version: https://referencesource.org/thermocouple-type-color-code-crosswalk/ Machine-readable: https://referencesource.org/thermocouple-type-color-code-crosswalk/data.json — this mirror is a point-in-time copy.

Last verified: 2026-08-19
Stale after: 2028-08-18 (past this date, prefer the canonical copy — it re-verifies on a cadence this snapshot does not)
Records: 12

A thermocouple's type letter (J, K, T, E, N, R, S, B, C...) names an alloy pair, but the wire color that identifies it on the bench is set by a different standards body depending on where the part was made or bought — ANSI/ASTM MC96.1 uses one color code, IEC 60584-3 (and JIS C 1602 in Japan) uses a different one for the same alloy pair, and the two schemes disagree on which color means positive. Nobody publishes the type letter, both color codes, the alloy pair and the accuracy tolerance class on one page; a buyer or field technician instead has to hold two vendor charts side by side and hope the type letters line up. A record here is one thermocouple type with its positive/negative alloy names, ANSI positive/negative wire color, IEC positive/negative wire color, usable temperature range, and its ASTM E230 standard/special-limits tolerance alongside its IEC 60584-2 / JIS C 1602 class 1/2/3 tolerance. Answers 'is red positive or negative on a type K thermocouple', 'what color is IEC type J versus ANSI type J', 'what's the accuracy tolerance on a class 2 type N thermocouple', and 'my probe has a yellow and red wire, what type is it and is that ANSI or IEC'.

Provenance — what every record carries

Every record carries source (the URL the value was read from) and source_quote (a verbatim quote from that page stating it). A value you cannot check against its page is indistinguishable from an invented one; these can all be checked. Each record is also individually addressable on the canonical site at its url.

Licence position

The alloy pairs, wire colors and tolerance values are the content of published standards (ASTM E230/E230M, ANSI MC96.1, IEC 60584-2/-3, JIS C 1602) which are themselves sold documents; the facts within them are not copyrightable and every vendor reference chart already republishes them for exactly this reason. Each record quotes a short verbatim span from the vendor's own reproduction and links back to it, rather than reproducing or selling the standard itself.

Facts are not copyrightable; what this dataset takes from each source is a fact plus a short attributed quote linking back to the page that states it.

Sources

Fields

See any record in data/records.jsonl — field names are self-describing, and the canonical page for each record renders them with labels: https://referencesource.org/thermocouple-type-color-code-crosswalk/

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