- Interfaces to Types J, K, T, R, and S Thermocouples
- High-Level Voltage Output
- 1500Vrms Isolation
- ANSI/IEEE C37.90.1 Transient Protection
- 120dB CMR
- 70dB NMR at 60Hz
- ±0.05% Accuracy
- ±0.02% Linearity
- Low Drift with Ambient Temperature
8B modules are an optimal solution for monitoring real-world process signals and providing high-level signals to a data acquisition system. Each 8B37 nonlinearized module isolates, filters, and amplifies a single channel of temperature input from a thermocouple input signal and provides an analog voltage output.
The 8B37 can interface to industry standard thermocouple types J, K, T, R, and S and has an output signal of 0 to +5V. Each module is coldjunction compensated to correct for parasitic thermocouples formed by the thermocouple wire and screw terminals on the mounting backpanel. Upscale open thermocouple detect is provided by an internal pull-up resistor.
Signal filtering is accomplished with a 3-pole filter optimized for time and frequency response which provides 70dB of normal-mode rejection at 60Hz. One pole of this filter is on the field side of the isolation barrier for anti-aliasing, and the other two are on the system side.
A special input circuit on the 8B37 module provides protection against accidental connection of power-line voltages up to 240VAC. Clamp circuits on the I/O and power terminals protect against harmful transients. These modules are designed for installation in Class I, Division 2 hazardous locations and have a high level of immunity to environmental noise.