why pressure gauges fill with oil?

Question

pressure gauges in cnc machines and hydraulic machines are fill with oil. what the reason to fill the oil in pressure gauges.

Answer 1

Two common reasons for gauge (and switch) failure are pipe vibration and water condensation, which in colder climates can freeze and damage the gauge housing. The delicate links, pivots, and pinions of a traditional gauge are sensitive to both condensation and vibration. The life of the filled gauge is longer, not only because it has fewer moving parts, but because its housing is filled with a viscous oil. This oil filling is beneficial not only because it dampens pointer vibration, but also because it leaves no room for humid ambient air to enter. As a result, water cannot condense and accumulate. Available gauge features include illuminated dials and digital readouts for better visibility, temperature compensation to correct for ambient temperature variation, differential gauges for differential pressures, and duplex gauges for dual pressure indication on the same dial.

Answer 2

an oil fillede guage is more accurate because pressure is put on the fluid and then fluid is pushed toward the guage the guage then reads the presssure change directly otherwise you would havean air seal in between the gauge and the area where you are trying to read pressure changes. the expansion and contraction of liquid can be more accurately measured than ex. and contr. of air

Answer 3

It's to keep the needle stable. Without the oil the needle tends to shake a bit, But the oil keeps it steady for a more accurate reading.