Thermocouple Measurement Wildcard™
precisely transduces temperature from one or two thermocouples of any type
Overview
The Thermocouple Measurement Wildcard is designed to allow easy and accurate measurement of wide ranging temperatures. Thermocouple measurement is described in detail here: Using Thermocouples.
Briefly, a thermocouple comprises two wires with dissimilar metals. It generates a small voltage that varies with temperature, offset by the "cold junction" potential that varies with the temperature present where the wires originate (in this case, at the Thermocouple Measurement Wildcard).
Thermocouples can measure a wide range of temperatures. For example, the popular type K thermocouple can measure temperatures between -250°C and +1200°C. The thermocouple voltage is a nonlinear function of temperature. Accurate temperature measurement requires low-noise high-resolution (16-bit) acquisition of the thermocouple voltage, measurement of the cold junction temperature, proper compensation of the cold junction voltage, and applying an accurate curve-fit model to transform the compensated thermocouple voltage into a temperature. The Thermocouple Measurement Wildcard and its pre-coded software driver library perform these functions to simplify temperature measurement in your instrument control application.
The Thermocouple Measurement Wildcard is available in two configurations:
- A single-channel version (Part# W-TCM-1) includes a board-mounted thermistor for very accurate cold junction compensation, delivering one temperature measurement channel accurate to ±0.25°C without the need for calibration.
- A dual-channel version (Part# W-TCM-2) includes a board-mounted integrated circuit chip with jumper-selectable cold junction compensation for two thermocouples. This chip provides temperature measurement over wide ranges with cold junction compensation accurate to ±4°C, and ±0.25°C accuracy can be obtained with a single-point temperature calibration per channel.
Both versions support type E, J, K, R, S or T thermocouples. The single-channel version additionally supports type B and N thermocouples. You can mix and match the Thermocouple Measurement Wildcard with any of the growing family of WildCards.
Thermocouple Measurement Wildcard Specifications
| CHANNELS: |
One (using PN W-TCM-1), or
two (using PN W-TCM-2) |
ACCURACY
(set by cold junction comp): |
±0.25°C
(for W-TCM-1 uncalibrated; or W-TCM-2 with single-point calibrations).
For more details see accuracy section. |
| TEMPERATURE RANGES: |
Type B: +250 to +1820°C
Type E: -270 to +660°C
Type J: -210 to +870°C
Type K: -250 to +1230°C
Type N: -250 to +1300°C
Type R: -50 to +1768°C
Type S: -50 to +1768°C
Type T: -250 to +400°C |
| ANALOG TO DIGITAL CONVERTER: |
dual channel, 16 bit resolution, input range -56.25mV to +56.25mV, ~7 conversions/second |
| WILDCARD OPERATION TEMPERATURE: |
0 to +70°C |
| THERMOCOUPLE CONNECTIONS: |
Screw terminals |
| CURRENT: |
70 mA from 5V |
| WEIGHT: |
20gram |
| SIZE: |
2" x 2.5" x 0.365" (50.8mm x 63.5mm x 9.3mm) |
Documentation and Pricing
