Experiments investigating the use of semiconductors for low‐pressure measurements proved that thermistors give the best results. These experiments led to the construction of thermistor systems consisting of miniature thermistors fixed to thin metal foils. With these systems it is possible to measure pressure changes in the range of 1 to 10−6mm Hg. The problem of temperature compensation is discussed and it is shown that in the case of thermistors this problem may be resolved by means of the voltagevscurrent characteristics. A detailed description of the apparatus, including the gauge head as well as the electric circuit and the calibration curves, is given.