Open thermocouple tester system

摘要

A system for testing open thermocouples in a data acquisition system in which each of a plurality of thermocouples is sequentially read. Each thermocouple has an associated filter capacitor and resistance network and each has a different common-mode voltage with respect to a reference potential. Charging means is effective to charge each filter capacitor in sequence after a reading has been taken. For a normal thermocouple, the filter capacitor discharges through the associated resistance and thermocouple prior to the next sequential reading of that thermocouple. For an open thermocouple the filter capacitor remains charged indicating that the thermocouple is open at the time of the next sequential reading of that thermocouple.