You are using an outdated browser. For a faster, safer browsing experience, upgrade for free today.

TC1

8 Channels Thermocouple, LV A/D

A thermocouple is a temperature-measuring device typically consisting of two dissimilar conductors that contact each other at one or more spots. It produces a voltage when the temperature of one of the spots differs from the reference temperature on other parts of the circuit. Thermocouple temperature sensors are widely used for measurement and control, and can also convert a temperature gradient into electricity.

In contrast to most other methods of temperature measurement, thermocouple modules are self-powered and require no external form of excitation. The biggest limitation with the thermocouple is accuracy; system errors of less than 1° C can be difficult to achieve. Thermocouples are suitable for measuring over a large temperature range, up to 2300° C. Applications include temperature measurement for rocket and/or jet engines, gas turbine exhaust, diesel engines, and other MIL/AERO/INDUSTRIAL embedded or test processes. They are arguably less suitable for applications where smaller temperature differences need to be measured with high accuracy (i.e., the range 0 – 100° C with 0.1° C accuracy). For such applications resistance temperature detectors may be more suitable.

 

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.

Specifications
  • Number of Channels: Eight for thermocouple measurement
  • Input Interface: Independent differential input channels
  • A/D Converter: Independent 24-bit Sigma-Delta type (one for each channel)
  • Temperature Range: NIST temperature range (J, K, T, E, N, B, R, S thermocouple types)
  • Voltage Measurement Range: ±78.125 mV to an accuracy of ± 25 µV over operational temperature of -40 to 85° C
  • Overvoltage Input Tolerance: ±4 V continuous, ±50 V momentary duration limited to 100 ms (applied at signal input)
  • 50/60 Hz Noise Rejection: > 70 dB
  • CMR: 85 dB (minimum)
  • Differential Input Impedance: >10 KΩ
  • Digital Output: IEEE 754-2008 (binary32) programmable for ° C, ° F (programmed for temperature), 24-bit (signed), based on % FSR (±78 mV) (programmed for A/D)
  • Accuracy: Based on minimum update rate and w/thermocouple block I/F compensation; ±0.2° C (Type J/N), ±0.3° C (Type K), ±0.3° C (Type T/E), ±0.3° C (Type R/S), ±0.9° C (Type B), ± 0.2% FSR (programmed for raw A/D digital output)
  • Resolution: 0.01° (programmed for temperature)
  • Update Rate: Programmable between 3-4800 Hz
  • Thermo-Block Interface: Optional thermocouple interface for connection of up to 7 thermocouple sensors. Pt100 RTD sensor for cold junction compensation temperature.
  • BIT (Built-In-Test): Continuous background ‘online’ accuracy, OPEN detection capability.
  • ESD Protection: Designed to meet the testing requirements of IEC 801-2 Level 2. (4 kV transient with a peak current of 7.5 A and a Tc of approximately 60 ns)
  • Power: +5 VDC @ 480 mA typ.
  • Ground: Independent channels (common internal return), isolated from system ground.
  • Weight: 1.5 oz. (42 g)
Block Diagram

(Click diagram to enlarge)

Documentation
4/7/2021 10:22:38 AM
Accelerate Your Time-to-Mission™ With COSA®

NAI’s Configurable Open Systems Architecture™ (COSA®) offers a choice of over 70 smart I/O, communication, and Ethernet switch functions, providing the highest packaging density and greatest flexibility of any multifunction I/O board in the industry. Preexisting, fully-tested functions can be combined quickly and easily in an unlimited number of ways. Each I/O function has dedicated processing, unburdening the system Single Board Computer (SBC) from unnecessary data management overhead.

Related COSA® Products
Can’t find what you’re looking for?

North Atlantic's resource center is where you will find information on warranty and repairs, details of our Product Lifecycle Management and Configuration Management programs – and much more.

Visit Resource Center