Diagnostics-oriented system for thermocouple thermometry

Thermocouple temperature measurements in hostile environments are subject to insidious error. The nature and source of some problems are described. Quick detection, diagnosis, and correction of faulty behavior is necessary to reduce error and to separate valid from spurious segments of data. Complementary diagnostic measures are required. They must be timely, convenient, and economical. Three techniques were developed to provide these: branched thermocouple circuits, COMUX Scanners (combinatorial line multiplexers), and a comprehensive computer-oriented data base. The principles of these novel measurement tools and an associated data acquisition system (DAS) which now uses them for research on in situ energy recovery methods are described.