APD 4351 Universal Thermocouple Temperature Transmitters

The APD 4351 accepts a thermocouple temperature input and provides an optically isolated and linearized DC voltage or current output. The sensor type, temperature range and output range are field configurable. The input type is set with switches and its range is configured using front buttons, a multimeter and an input simulator. This provides a versatile solution that works with all commonly available thermocouple sensors. Microprocessor-based linearization uses 41 to 55 segments or up to a 14th order polynomial depending on the sensor type. The input is sampled, digitally converted to a linearized temperature signal and then passed through an optocoupler to the output stage. Full 3-way isolation (input, output, power) make this module useful for ground loop elimination, common mode signal rejection, and noise pickup reduction. The low noise 18 bit analog output is isolated and can be set up for common voltage and milliamp output types.