AMP-TC-LIN linearizing thermocouple amplifier, K and J 10 mV/°C

Linearizing thermocouple amplifier for K and J types

The AMP-TC-LIN is a modular spinning thermocouple amplifier for K and J thermocouples. It compensates the cold junction, amplifies and linearizes the signal: the output is 10 mV/°C over the whole input range, up to ± 10 V (0 °C = 0 V, 200 °C = 2 V). The input range is −80 to 1000 °C for type K and 0 to 750 °C for type J, with a bandwidth of 10 Hz at −3 dB. Temperature error, cold junction included, is ± 3 °C max from −40 to 70 °C case temperature and ± 5 °C max to 110 °C. It runs on ± 15 V DC, weighs 9.2 g and measures 30.99 × 19.23 × 5.46 mm without connectors.

Placed on the rotating side of a slip ring, close to the sensor, the amplifier reduces the errors that temperature gradients across dissimilar metals in the slip ring and magnetic interference add to the thermocouple signal. It can be adhered, potted or strapped to the part; the manual gives Dow Corning 3145 RTV for bonding. The length of the power and output leads can be specified, and the thermocouple input wires come with or without an Omega miniature connector. More channels take more than one amplifier on a single control unit; some Michigan Scientific slip rings come with the amplifiers built into the rotor.

A PS Series amplifier control unit supplies the ± 15 V and common; its bridge excitation and shunt calibration switches do not affect the amplifier. It is used, for example, to measure the temperature of rotating parts through a Michigan Scientific slip ring. An unused or open thermocouple input gives 0 V and does not damage the amplifier.