Water pressure test gauge - GIF

[hemmjo]

Which system of Metrickery?

Golden standard for domestic use in most countries is 55 P.S.I.- 3.279 bar - 284.4 cm of Mercury - 379.2 kilopascal -

oops, I think you might type like I do. 3.279 bar should be 3.792 ... 1bar = 100 kilopascal

In round numbers, I always remember from SCUBA diving, that 1 bar ≈ 1 atmosphere ≈ about 14.5 PSI ≈ 34 feet of water. At about 100 ft you are at 3 atmospheres, so you use your air 3 times faster and the air is actually "thicker" to breathe.