Simple dipstick cryostat with versatile temperature controller for high thermal stability

A simple dipstick type vapour cryostat and a versatile electronic temperature controller which uses a proportional, integral and differential type of control are described. They have been used together for the calibration of thermometers in the liquid helium temperature range and for the measurement of the transition temperature of superconductors. Temperature stability of 2 mK (typical) is achieved easily at a working temperature of 7 K for a period exceeding an hour. The use of the system is quite general and can readily cover the temperature range up to 300 K with a suitable choice of temperature sensor and heat input.