Thermocouples
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Durex Industries manufactures reliable and robust industrial thermocouple sensors. Thermocouples provide fast temperature response that can be applied in most temperature measurement and control applications. We are prepared to provide the best thermocouple temperature sensor solutions.
Product Technology Solutions
HOW THERMOCOUPLE SENSORS WORK
A thermocouple junction is a single point junction between two dissimilar metals. This junction creates a known millivolt level signal that changes as the process temperature increases or decreases. The millivolt signal is used as the temperature measurement input to a temperature controller.Depending on an application's process temperature range, accuracy specifications, and material compatibility, our sensors are available in Type K thermocouples, Type J thermocouples, Type E thermocouples, Type T thermocouples, Type S thermocouples, Type R thermocouples, and other dissimilar metal combinations. Durex Industries manufactures thermocouple temperature sensors that can be designed with grounded or ungrounded junctions and housed in insulated sheath materials that are designed for best form fit in the applications.
CONSIDERATIONS WHEN DECIDING BETWEEN GROUNDED AND UNGROUNDED JUNCTIONS
Grounded thermocouple junctions physically touch the metal sheath of the temperature probe, and they are electrically grounded. This physical connection gives them a faster response time, but it can also make them susceptible to electrical noise. These stray voltages can interfere with the accuracy and control of measurement.Ungrounded thermocouple junctions, however, are not susceptible to electrical noise issues because there is no physical or electrical contact between them and the metal sheath of the temperature probe. This lack of contact does reduce the response time to temperature changes, however.
CUSTOM THERMOCOUPLE TEMPERATURE SENSORS
Durex Industries has been engineering and manufacturing quality custom thermocouples for over 40 years. Our engineering team will assist you with a thermocouple sensor design that fits your application requirements.Ask us how we can help you with your OEM product roll-out. To learn more about our thermocouple sensors and how Durex can help you, contact us today.
Need help deciding which type of temperature sensor is right for your application, view our temperature sensor element selection guide.
Thermocouples Specs & Options
Back to TopDurex offers testing at standard temperatures for determination of initial calibration tolerances for thermocouples. All calibration tests are fully traceable to the National Institute of Standards and Technology (NIST). Calibration is also available for application temperatures other than the standard points in a range from -100°F to 3000°F (-79°C to 1650°C) depending on material. Certificates are supplied for all items calibrated.
Thermocouple Calibration
| Calibration (T/C Type) | Temperatures Available | Applicable Specifications |
|---|---|---|
| Type E, J, K, T Thermocouples | 32°F to 2300°F(0°C to 1250°C) | ASTM E 207 / ASTM E 220 |
| Type R, S Thermocouples | 32°F to 3000°F(0°C to 1649°C) | ASTM E 230 / ANSI MC 96.1 |
| Type E, K, T Thermocouples | -320°F & -110°F to 23°F(-196°C & -79°C to 0°C) |
Durex manufactures thermocouple assemblies in the following calibration options.
| ANSI Letter | Durex Code and Calibration | Calibration Description |
|---|---|---|
| Type E Thermocouple | E / Chromel P-Constantan | Standard Limits 32°F to 1652°F (0°C to 900°C) 1.7°C or 0.5% Tol. |
| Special Limits 32°F to 1652°F (0°C to 900°C) 1.0°C or 0.4% Tol. | ||
| Type J Thermocouple | J / Iron - Constantan | Standard Limits 32°F to 1382°F (0°C to 750°C) 2.2°C or 0.75% Tol. |
| Special Limits 32°F to 1382°F (0°C to 750°C) 1.1°C or 0.4% Tol. | ||
| Type K Thermocouple | K / Chromel P-Alumel | Standard Limits 32°F to 2282°F (0°C to 1250°C) 2.2°C or 0.75% Tol. |
| Special Limits 32°F to 2282°F (0°C to 1250°C) 1.1°C or 0.4% Tol. | ||
| Type T Thermocouple | T / Copper-Constantan | Standard Limits 32°F to 662°F (0°C to 350°C) 1.0°C or 0.75% Tol. |
| Special Limits 32°F to 662°F (0°C to 350°C) 0.5°C or 0.4% Tol. | ||
| Type R Thermocouple | R / Pt 13% Rhodium-Platinum | Standard Limits 32°F to 2642°F (0°C to 1450°C) 1.5°C or 0.25% Tol. |
| Special Limits 32°F to 2642°F (0°C to 1450°C) 0.6°C or 0.1% Tol. | ||
| Type S Thermocouple | S / Pt 10% Rhodium-Platinum | Standard Limits 32°F to 2642°F (0°C to 1450°C) 1.5°C or 0.25% Tol. |
| Special Limits 32°F to 2642°F (0°C to 1450°C) 0.6°C or 0.1% Tol. |
Thermocouple Sheath Diameter Specifications
| Sheath Code | T | Y | W | A | B | V | C | D | E | F | H |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Sheath Diameter | .020" | .032" | .040" | .062" | .125" | .156" | .188" | .250" | .313" | .375" | .500" |
| Wire Gauge | 38 | 34 | 33 | 30 | 24 | 22 | 20 | 18 | 16 | 15 | 11 |
| Maximum Length | 100' | 150' | 200' | 400' | 250' | 200' | 175' | 100' | 55' | 40' | 30' |
Thermocouple Specifications
Sheath - Tolerances: Outside diameter ± 0.002” of nominal size.
Insulation - High purity magnesium oxide is standard; ultra high purity magnesium oxide and alumina oxide are available.
Configurations - Sheath diameters available from 0.020" to 0.500". Two wire (single circuit) and four wire (double circuit) configurations are standard in most diameters.
Formability - Minimum radiums: 2X sheath diameter for most thermocouple materials. Consult Durex Industries if special forming is required.
Weldability - Thermocouple sheath can be brazed, soldered, or welded without loss of insulation resistance. Welding of special sheath materials by the customer is not recommended.
Physical Testing
- Dimensional and visual
- Helium leak
- Radiographic (X-Ray)
- Dye Penetration
- Metallurgical per ASTM E-2, E-3, and E-112
- Compaction density per RDT C2-IT
- Calibration per ASTM E-220 traceable to NIST
- Insulation resistance
- Wire resistance (ohms per foot loop)
- Time response per RDT C2-3T
- Thermal cycling per ASTM E-225
- ASTM E585 Standard specifications for sheathed based-metal thermocouple materials.
- ASTM E608 Standard specifications for metal-sheathed base-metal thermocouples.
- ASTM E780 Standard method for measuring the insulation resistance of sheathed thermocouple-material at room temperature.
- ASTM E839 Standard test methods for sheathed thermocouples and sheathed thermocouple material.
Insulation Resistance
| Nominal Sheath Outside Diameter | Applied D.C. Voltage (min.) | Insulation Resistance MegΩ |
|---|---|---|
| .030” Diameter and smaller | 50 | ASTM E 207 / ASTM E 220 |
| .030” Diameter and smaller | 50 | ASTM E 230 / ANSI MC 96.1 |
| .062” Diameter and larger | 500 | 1000 |
Custom Options Available - Contact us for Engineering Assistance.
Thermocouples Applications
Back to TopThermocouple sensors are used in a wide variety of applications. They can be used in cryogenic temperatures to molten steel above 1500C.
You can commonly find industrial thermocouples in:
- Metals Processing (Aluminum, Steel, and other metals)
- Ovens, Furnaces, Kilns
- Plastic Processing
- Food Processing and Preparation
- Chemical and Petro-Chemical Processing
- Pulp & Paper Mills
- Power Generation Plants
- Engines
Thermocouples Case Studies
Back to TopTemperature Sensors for Food Service Oil Processing Equipment
Temperature Probes For Analytical Instrumentation
Exhaust Gas Temperature Sensors
Temperature Sensors For Aerospace Industry
Pressure Washer Temperature Sensors
Melt Bolt Thermocouple Sensors For Extruder Lines
Precision RTDs For Foodservice Equipment
Custom Temperature Sensor Development Capabilities
Thermocouples Downloads
Back to TopIndustrial Thermocouples Catalog 0115-1MB
Mineral Insulated Thermocouples Catalog 0115-1MB
Plastics / General Purpose Thermocouples Catalog 0115-1MB
Temperature Sensors Catalog 0115-4MB
Temperature Sensor Element Selection Guide 200KB
Technical Data - Thermocouple Wire Code Standards 0115-250KB