Pirani gauge

instrument

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Last updated

July 1, 2026

Quick Summary

A Pirani gauge is a type of hot-wire manometer used to measure pressure in a vacuum system. It operates on the principle that the cooling effect on a heated filament is related to the pressure of the surrounding gas. As gas molecules collide with the filament, they carry away heat. At lower pressures, there are fewer molecules, resulting in less cooling and a higher filament temperature. The gauge measures this change in filament temperature, typically by detecting a change in its electrical resistance, to infer the pressure. Pirani gauges are useful for measuring pressures in the range of 100 to 10^-4 torr.12

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vacuum technology
Thermal conductivity gauges
…of thermal conductivity gauges, the Pirani and the thermocouple, determine pressure by the rate at which heat is dissipated from a hot filament. The Pirani gauge basically is a Wheatstone bridge with one arm in the form of a heated filament placed in the vacuum system. The resistance of the…
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…of thermal conductivity gauges, the Pirani and the thermocouple, determine pressure by the rate at which heat is dissipated from a hot filament. The Pirani gauge basically is a Wheatstone bridge with one arm in the form of a heated filament placed in the vacuum system. The resistance of the…
Read More