National Instruments SCC-RTD01 Resistance Temperature Detector Input Module

The SCC-RTD01 (Part Number: 777459-18) Resistance Temperature Detector (RTD) is an input module that acknowledges up to two RTD input signals from 2-, 3-, or 4-wire RTDs. Every module comprises of two RTD input channels, a 30 Hz Butterworth low-pass filter for each channel, and a 1 mA excitation current source. Each input channel incorporates an instrumentation amplifier with differential inputs and a fixed gain of 25. This model filters RTD inputs and passes them through a differential amplifier with a fixed gain of 25, resulting in a maximum input voltage of ±400 mVDC. The output of the amplifier goes through a three-pole, 30 Hz Butterworth low-pass filter. This model also gives a 1 mA excitation source for RTDs. It has an overvoltage protection of ±42 VDC when powered on, and ±25 VDC when powered off.

The National Instruments SCC-RTD01 has six pins and gives two differential AI channels for estimating the voltage crosswise over RTDs. Pins 1 and 2 create a differential channel directed to E/M Series DAQ model channel X+8, while pins 3 and 4 create a second differential channel routed to E/M Series DAQ gadget channel X, where X is 0 to 7 depending on the socket of the NI SCC-RTD01. Pins 5 and 6 carry the 1 mA consistent current excitation source. The device is equipped with a 20-pin right-angle male connector and a 6-pin screw terminal. It has maximum analog and digital power requirements of 135 mW and 153 mW respectively.

NI programming environments incorporate SCC–RTD01 RTD conversion utilities that actualize the voltage-to-temperature changes. Although the NI SCC–RTD01 protection versus-temperature bend is moderately linear, precisely converting resistance to temperature requires curve fitting. The Callendar-Van Dusen equation is normally used to approximate the RTD curve.

The SCC-RTD01 weighs 0.8 oz (24 g). The device has a recommended operating temperature range of 0 to 50 °C, a storage temperature range of –20 to 70 °C, and a non-condensing relative humidity range of 5 to 90%. It is designed to comply with the following electrical safety standards: IEC 61010-1, EN-61010-1, UL 61010-1, and CAN/CSA-C22.2 No. 61010-1.