Design and development of temperature controller for thermostat hot reference junction

Reference junction constitutes an integral part of any thermo-couple temperature measurement system. Maintaining cold or hot reference junction at constant temperature is a pre-requisite to obtain accuracy in the measured temperature. The paper describes the design and development of a simple temperature controller to replace the bi-metallic type controller, which are either not available or obsolete, in the thermostat hot reference junctions which have been imported in large quantities along with Creep Testing Machines in the Central High Temperature Material Testing Facility.