Device for measuring the absolute pressure of air

摘要

A device for measuring the absolute pressure of air is specified, which manages without the use of mechanically stressed diaphragms. The device is based on a polarographic measuring cell which operates according to the principle of the diffusion limit current and consists of a solid electrolyte member which conducts oxygen ions and supports an anode and a cathode, which is exposed to the air to be measured and to which a constant voltage can be applied. The cathode supports a porous diffusion layer whose pores have diameters which are small by comparison with the mean free path length of the oxygen molecules. The pores have diameters of less than or equal to 0.1 mu m. In addition, the device is further fitted with a controlled heater, which is applied to the diffusion layer. <IMAGE>