Gauge pressure or absolute pressure?
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May I ask, in the equation for the adiabatic reversible process of an ideal gas, PV^γ = constant, does P refer to absolute pressure or gauge pressure? How is it determined whether P in the general formula refers to absolute pressure or gauge pressure? Thank you all~
. . . . . As I understand it, the formula uses only absolute pressure.:) . . . . . .
It should be absolute pressure; in engineering, gauge pressure is more commonly used, while absolute pressure is used in theory.
I am using this formula to calculate the exhaust volume at the outlet of the compressor in an ammonia refrigeration plant; should absolute pressure be used in the calculations? What do you mean by gauge pressure, which is commonly used in engineering? Doing these calculations is also part of engineering calculations
In engineering terms, it refers to the pressure indicated by the gauge, or the pressure unless otherwise specified.
In other words, calculations in engineering also use gauge pressure~ What you mentioned about using a pressure gauge refers only to actual production situations. Is that what you mean?
In books and theoretical calculations, absolute pressure is used, but in practice gauge pressure is used, which is the reading on a pressure gauge
Unless otherwise specified, all values are gauge pressure. . . . . . . . . . . . . .
The pressure indicated by a pressure gauge generally does not require any specification – it refers to gauge pressure
It should generally be indicated; gauge pressure should be marked as (a), and absolute pressure as (g).
Theoretical calculations generally refer to absolute pressure; a suffix of ‘a’ can be added thereafter. Gauge pressure usually has the suffix ‘g’