A Temperature Control System for a Variable Temperature Cryostat Using an 80386 Personal Computer

We report on the development of an automatic temperature control system for a variable temperature cryostat operating from 4.2 – 100 K. The large changes that occur in system heat capacity and cooling power over the range of operating temperature have led to the development of a segmented linear control system. The control system has been implemented on an IBM compatible 80386 personal computer which communicates with an external DMM and power supply via IEEE 488 interface. Temperature transducers are carbon glass and platinum resistance thermometers.