What is absolute reference pressure and absolute reference temperature

AI Thread Summary
Absolute reference pressure is defined as pressure measured relative to a perfect vacuum, typically represented as 0 Pa, while absolute reference temperature is measured in Kelvin, referencing absolute zero. Standard conditions are often cited as 1.01 bar and 273+25K, but these are relative to a standard environment. The normal state refers to 1.01 bar and 273K, which is also a relative measure. In tests involving compressed air flow rates, it's crucial to distinguish between absolute and relative measurements to ensure accuracy. Understanding these definitions is essential for proper calculations in various scientific and engineering applications.
Su Solberg
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What is "absolute reference pressure and absolute reference temperature"

I am doinf a test about compressed air flow rate.
There is a parameter called absolute reference pressure and absolute reference temperature.
Are they 1.01bar and 273+20K?
 
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Those what you wrote 273+25 and 1.01bar are the called "standard" state,
There is another one called the "normal" state which is 273 and 1.01,
I don't know absolute can mean here.., probably one of the above two...
 


Not sure but would relative pressure be a pressure relative to an absolute pressure, i.e absolute pressure "being that of space".. conventionally 0 Pa due to a void of particles..Although it does depend what kind of pressure you are talking about, space itself being is probably some form of energy resulting in a pressure "off" space. But i suppose that may beside the point.
In your case, in the test, i would say the reference pressure is with respect to a vacuum. If the atmospheric pressure is adding to the absolute pressure, then you would have to substract the atm pressure (101.3 KPa ) from the relative pressure in order to obtain the absolute pressure (with respect to vacuum). The absolute reference pressure may be directly measured with respect to the vacuum by creating a vacuum.
As for temperature, along the same lines i would say absolute temperature is temperature in kelvin, i.e with respect to absolute zero.
As for : Are they 1.01bar and 273+20K? These would be relative pressure and temperature, relative to a "standard environment".
May be wrong though..

Does that help at all?
 
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