Abstract: A low temperature solid state light detecting system is disclosed. The same incorporates a source of cooling and an electrical light detector. A heat conducting member extends from the detector chip to the source of cooling. A vacuum chamber contains the light detector. The chamber has a window for permitting light to fall on the electrical light detector. A plurality of electrical feedthrough devices are mounted on the chamber for coupling electricity from inside the chamber to the outside of the chamber. A plurality of bare wires extends from the detector to the feedthrough devices positioned on the housing.

Abstract: 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.