A thermocouple is widely used across process industries for accurate temperature measurement and control. It features an electrical junction made of two dissimilar metals. This junction produces an electric signal when it experiences a variation in temperature. At Therm-x, we provide different types of thermocouple sensors, which are designed with or without grounded junctions. We provide thermocouple sensors of various types. Some prominent ones include type E, J, K, N, T, B, C, and R/S. These thermocouple sensors are distinguished based on their junction alloys. These junction alloys also contribute to the temperature range and accuracy of these thermocouple sensors. Owing to their rugged construction, our thermocouple sensors are proven to perform in diverse complex environments. Our advanced sensor manufacturing capabilities coupled with the industry experience has helped us become one of the leading thermocouple suppliers in the US. We regularly provide thermocouple sensors to our clients across semiconductor processing, automotive engineering, food and beverage processing, medical equipment, and other industries.
As a custom thermocouple manufacturer, we prioritize customers’ temperature measurement requirements before other factors. Our thermal experts combine their industrial experience, expertise, and in-depth understanding of temperature control requirements to provide appropriate solutions to customers. When it comes to customized thermocouple sensors, our team helps customers customize their products with the right thermocouple probes in different sheath diameters and surface finishes.
Many mission-critical and temperature-sensitive applications require quality, certifications, and testing. All our thermocouple products are built to ASTM tolerances and conform to the International Temperature Scale of 1990. Our thermocouple wires conform to ASTM E230 specifications.

Custom Options
- Single or Multi Point
- Helium Leak tested
- Optional Calibration
- Bendable
- Optional screw on and spring loaded bushings
- Operating temperatures -50°C – 500°C
- Accuracy dependent on TC type
- Electro polished
- Passivated
- Clean room packaged


Spring loaded Thermocouples
These thermocouples work great in any industry and operate in in vacuum or gases. Spring loaded tip and threaded bushing ensure intimate contact and repeatability.

Custom Options
- Type K Special limits of error
- Helium Leak tested
- Optional Calibration
- Bendable
- Electro polished
- Passivated
- Clean room packaged
- Threaded spring loaded bushings


Mineral Insulated Thermocouples
M.I Cable Thermocouples
Mineral Insulated Thermocouples (MI) thermocouples consist of matched thermocouple wires surrounded by insulating material (typically magnesia oxide) compacted by drawing or swaging the sheath. The result is a rugged and reliable construction suitable for a wide variety of applications including Semiconductor wafer processing, heat treating, medical, nuclear reactors, refineries and oil processing, vacuum furnaces, laboratory and research, etc. Advantages of mineral insulated thermocouples are:
- Useable under severe conditions
- Withstands temperatures up to metal melting point
- Withstands corrosive conditions limited only by the choice of sheath material
- Can be formed to a minimum radius of twice the sheath diameter without loss of integrity
- Can be welded, brazed or soldered to other metals when proper techniques are used
- Can be formed to a minimum radius of twice the sheath diameter without loss of integrity
- Available in a wide variety of diameters from .010” to .500”
- Available in standard and special limits of error
- Can withstand external pressures up to 50,000 psi
- Multiple element cable is available
M.I. Cable Specifications
- Sheath Diameter: ± .002" or ± 1% of nominal diameter, whichever is greater.
- Wall Thickness: ± .0015" or ± 15% of nominal wall thickness, whichever is greater, 10% of diameter as a minimum.
- Insulation Material: 98% (min.) MGO Magnesium Oxide
- Insulation Temp.: Insulation is useable over a temperature range of -450°F to 3000°F without change of phase or chemical reaction with adjacent metals. Melting temperature of insulation is 4800°F. Limiting temperature is associated with sheath material used.
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Thermocouple Wire Specifications | ||||||
T/C Type | Single color | Ansi Color Coding Overall Extension |
Overall thermocouple | Conductor Alloys | Temperature Range°F(°C) Thermocouple Grade Extension Grade |
Tolerance(standard) / whichever is Greater |
Tolerance(Special) / whichever is Greater |
E | Purple Red |
Purple | Brown | EP/EN Chromel/Constantan | -328 to 1652 (-200 to 900) 32 to 392 (0 to 200) |
+-1.7 deg C or +-0.5% |
+-1.0 deg C or +-0.4% |
J | White Red |
Black | Brown | JP/JN Iron/Constantan | 32 to 1382 (0 to 750) 32 to 392 (0 to 200) |
+-2.2 deg C or +-0.75% |
+-1.1 deg C or +-0.4% |
K | Yellow Red |
Yellow | Brown | KP/KN Chromel/Alumel | -328 to 2282 (-200 to 1250) 32 to 392 (0 to 200) |
+-2.2 deg C or +-0.75% |
+-1.1 deg C or +-0.4% |
N | Orange Red |
Orange | Brown | NP/NN Nicrosil/Nisil | -450 to 2372 (-270 to 1300) 32 to 392 (0 to 200) |
+-2.2 deg C or +-0.75% (2% below 0 deg C) |
+-1.1 deg C or +-0.4% |
T | Blue Red |
Blue | Brown | TP/TN Copper/Constantan | -328 to 662 (-270 to 350) 32 to 392 (0 to 200) |
+-2.2 deg C or +-0.75% (1.5% below 0 deg C) |
+-0.5 deg C or +-0.4% |
B | Grey Red |
Grey | None | BP/BN Platinum 30% Rhodium Platinum 6% Rhodium |
32 to 3092 (0 to 1700) 32 to 212 (0 to 100) |
+-3.7 deg C or +-0.5% over 800 deg C |
NOT ESTABLISHED |
C | White Red |
White Red Trace |
None | CP/CN Tungsten 5% Rhenium Tungsten 26% Rhenium |
32 to 4208 (0 to 2320) 32 to 1600 (0 to 870) |
+-4.5 deg C to or 425 deg C 1% to 2320 deg C |
NOT ESTABLISHED |
R/S | Black Red |
Green | None | RP/RN R=Platinum/13% Rhodium S=10% Rhodium/Pure Platinum |
32 to 2462 (0 to 1450) 32 to 300 (0 to 150) |
1.5 deg C or .25% | .6 deg C or .1% |