National Instruments FP-TC-120 Thermocouple Input Module

The NI FP-TC-120 (Part Number: 777518-120) is an 8-input channel, FieldPoint Thermocouple Input Module. This module features four voltage ranges, cold-junction compensation, and built-in linearization for eight thermocouple types: B, J, R, K, S, N, T and E. Moreover, the NI FP-TC-120 comes with an open-thermocouple detection feature. The device is equipped with a Delta-sigma ADC type which has a resolution of 16 bits. It is equipped with four voltage ranges: ±25, ±50, ±100, and –20 to 80 mV.

This Thermocouple Input Module has eight differential input channels, which all share an isolated, common ground reference. Each channel is updated at 1.13 s. To generate a reading in temperature units, the FP-TC-120 linearizes the input that it receives in the form of a thermocouple voltage. With this module, the user can receive readings in three ranges: –454 to 3,218 °F, 0 to 2,048 K, and –270 to 1,770 °C. Temperatures beyond these ranges result in triggering an out of range error for the respective channel(s). The device is fitted with filtering against 50 Hz and 60 Hz noise.

The National Instruments FP-TC-120 is offered with preloaded algorithms for measurement linearization, according to the NIST-175 standard. This standard defines thermocouple characteristics based on the International Temperature Scale ITS-90. When the user chooses a temperature range for any channel, the open-thermocouple detection mechanism for that channel turns on automatically. In the case of an open thermocouple, the corresponding red LED lights up. The device is installed by mounting the FP-TC-120 on a FieldPoint terminal base. It has an input bandwidth of 3 Hz, with an overvoltage protection of ±40 V, an input current of 35 nA typ, 140 nA max, and an input noise of ±1 LSB peak-to-peak.

This Thermocouple Input Module features cold-junction compensation that turns on when a temperature range is selected. The FieldPoint FP-TC-120 Thermocouple Input Module takes over from the network module and consumes around 350 mW of power. This National Instruments FieldPoint Module can be operated within a broad temperature range of -40 to 70 °C, and a recommended storage temperature range of –55 to 85 °C. The device weighs 4.8 oz.