Thermocouple and/or RTD Sensor Measurement Interface


Thermocouple and/or RTD Sensor Measurement Interface (TR1)

Module TR1 is NAI’s latest generation Thermocouple/RTD Sensor Measurement Module. This module is used on our rugged COTS Multifunction Embedded I/O Boards, Single Board Computers (SBCs), and Configurable Systems offered in OpenVPX, cPCI, VME, and PCI/PCIe configurations. The module is designed for use in rugged embedded as well as test & measurement applications.

Our Smart Function Modules provide uniquely flexible, mix & match customization options for use with our COTS hardware. Learn More

Module TR1

The TR1 provides eight channels which can be individually programmed as a Thermocouple (TC) or a Resistance Temperature Detector (RTD) measurement interface. When configured as a TC, the channel can interface with virtually all thermocouple-type NIST temperature ranges. When configured as an RTD, the channel can interface to two, three and four-wire platinum RTD sensor configurations.

The TR1 channels are individually configurable for up to 8 isolated TC or low-voltage range A/D measurement channels. Configuration programmability provides interfaces for industry standard NIST thermocouple types (J, K, T, E, N, B, R, and S).

The TR1 channels are individually configurable for up to 8 isolated RTD measurement channels. Each channel is configurable for use with 4-wire, 3-wire or 2-wire connections to the RTD sensors. All RTD channels are calibrated at the factory and measurement results provided in Single Precision Floating Point Value (IEEE-754) format.

TR1 Block Diagram

Feature Summary

  • Thermocouple Measurement
    • Interfaces with most standard NIST thermocouple types (J, K, T, E, N, B, R, and S)
    • Self-powered
    • Large temperature range; up to 2300° C
    • Accuracy up to ±0.2° C (thermocouple type dependent)
    • Thermo-block compensation option P/N ACC-ISO-THERM-BLK2 (If accessory used, channel 8 is automatically allocated as an RTD interface for the thermo-block compensation temperature measurement)
  • RTD Measurement
    • Higher accuracy and repeatability as compared with thermocouples in applications below 600 °C
    • Two, three or four-wire mode
    • Channels are calibrated at the factory for Pt100, Pt500, and Pt1000 RTDs
    • Single Precision Floating Point Value (IEEE-754) format
    • Open sensor connections are detected and reported
    • 1 mA, 500 µA & 250 µA excitation sources for Pt100, Pt500 & Pt1000 ranges
  • Independently Programmable 
    • Up to 8 RTD channels
    • Up to 8 Thermocouple channels 
  • Independent Mode Select
    • Configures Thermocouple or RTD
  • Programmable Sample Rate
    • Sets the sampling rate of the A/D 
  • Offset Temperature 
    • Provides ability to null for any system induced measurement errors 

External Thermo-block Interface

View ACC-ISO-THERM-BLK2 Datasheet

Equipped with an externally mounted (~3.0” x 1.75” x 0.75") iso-thermal interface/therminal block (optional accessory) for housing a cold-junction-compensation temperature sensor, the TC1 has a direct interface and automatically provides compensated measurements at accuracies up to ±0.2° C. As an option for certain rugged embedded systems and applications, the junction temperature offsets may be directly programmed for standalone operation or via ambient/junction temperature measurement by other means including internal temperature sensor.

The fundamental design is based on independent 24-bit Sigma-Delta A/D converters for each channel; therefore, the TC1 can be alternatively programmed and used for direct precision, low voltage measurements (±100 mV) in other low-voltage range A/D applications (i.e., shunt resistor voltage/current sense measurements).

The TC1 is designed for rugged, embedded “on-the-move” or laboratory-grade environments, and provides continuous Background Built-in-Test (BIT) capabilities for accuracy and “open” detection monitoring and flagging.


Click below for manuals and specifications:

TR1Independent 24-bit Sigma-Delta type (one for each channel) TR1 DatasheetTR1 Manual