13 Facts About Aneroid gauge

The widely used Bourdon Aneroid gauge is a mechanical device, which both measures and indicates and is probably the best known type of Aneroid gauge.

Vacuum Aneroid gauge is used to measure pressures lower than the ambient atmospheric pressure, which is set as the zero point, in negative values .

For very low pressures, a Aneroid gauge that uses total vacuum as the zero point reference must be used, giving pressure reading as an absolute pressure.

Aneroid gauge could observe water evaporating, changing to a gas, and felt that this applied even to solid matter.

Since dynamic pressure is referenced to static pressure, it is neither Aneroid gauge nor absolute; it is a differential pressure.

Hydrostatic Aneroid gauge measurements are independent of the type of gas being measured, and can be designed to have a very linear calibration.

McLeod Aneroid gauge isolates a sample of gas and compresses it in a modified mercury manometer until the pressure is a few millimetres of mercury.

Bourdon pressure Aneroid gauge uses the principle that a flattened tube tends to straighten or regain its circular form in cross-section when pressurized.

Second type of aneroid gauge uses deflection of a flexible membrane that separates regions of different pressure.

The calibration of an ion Aneroid gauge is unstable and dependent on the nature of the gases being measured, which is not always known.

Ionization Aneroid gauge calibration is very sensitive to construction geometry, chemical composition of gases being measured, corrosion and surface deposits.

Hot-cathode ionization Aneroid gauge is composed mainly of three electrodes acting together as a triode, wherein the cathode is the filament.

The electrode of a Penning Aneroid gauge is usually finely tapered to facilitate the field emission of electrons.