Dewpoint Measurement (pressure vs. ambient)

[toothless]

I realize when most people talk about the dewpoint of their instrument air they are assuming the dewpoint measurement was made at line pressure. This is the pressure dewpoint.

I currently have our dewpoint analyzers set up to measure the dewpoint at very low pressure, then I do the conversion to pressure dewpoint. I do this because I figure there is less risk of sending liquid water (during an upset) to the dewpoint probe.

Does this seem appropriate, or will measuring the dewpoint near ambient pressure not produce accurate results? I appreciate any helpful input.

 

[quark]

The primary aim of calculating or indicating atmospheric dew point is to check whether the product or equipment, where you are using the air, will be safe or not. Most of the applications expand air before using it or compressor air gets expanded when you are using it. So it is always better to check ADP rather than PDP. There is no harm in it.

PS : As low pressure air always holds more moisture, we dry it when it is compressed for energy optimisation.

Regards,

 

[hacksaw]

you can refer the dew point to either condition just be consistent. it is not a well defined variable in that it depends on the measurment technique used.