Abstract
A cryostat designed primarily for intercomparison of platinum resistance thermometers in the range 10 to 300 K is described. A vented, ``inverted'' Dewar is introduced as a simple means to provide both rapid cool‐down and thermal isolation without the necessity of temporary vacuum seals. Adiabatic conditions are automatically maintained, resulting in a system easily stabilized to within 30 μK/min throughout the entire range.