A Barometer for Remote Locations and Data Buoys

A new type of barometer, based on the sprinciple of the vapour pressure thermometer is described. Instead of measuring the equilibrium vapour pressure to determine the temperature the temperature at which the vapour pressure matches ambient pressure is measured to determine the barometric pressure. The barometer can operate at power levels of 20-25 mW or less and since it is based on a fundamental property of the pure substance should have exceptional stability, say 20 Pa ( atmos.) indefinitely. Current models give dc output variation of 0.5V/kPa over the normal barometric pressure range. A higher power version (200 mW) allowing much less sophisticated filling procedures is also described.