And we shall not speak of pressure in inches of water.... :-) The only reason inches of water still exists as a pressure measurement is that it's incredibly simple to measure as a differential pressure in air systems. U shaped or V shaped tube, pour in water. Apply differing pressures across both ends, and measure the inches of water difference. Assuming one end didn't suck the water in because it exceeded the gauge limit....
SRK
Dag Bonnedal Wrote:
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> Pressure units can confuse anyone, sorry for
> adding to this.
> One "atmosphere" was in old metric units defined
> as one kilo per square cm. But in this case it is
> not kilogram, as this is a unit of mass, not
> force.
> In old units the "weight" (force of gravity) of
> the mass of 1 gram was called "pond", abbreviated
> p. Thus the unit of "atmosphere" was more
> correctly written as kp/cm2 (kilopond per square
> cm). When the SI-unit for force was defined as
> Newton (N) and pond was phased out, the standard
> unit of pressure was defined as "bar" (1 bar =
> 0.981 atmosphere). And more recently the correct
> SI-unit Pascal has been spread all over the
> SI-world, 100 kPascal = 1 bar.