Re: NG 2-12-2T boiler pressure

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.



Edited 1 time(s). Last edit at 10/26/2020 04:06PM by Dag Bonnedal.