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[chemtan]

What is the formula to calculate compensated flow for a DP Type transmitter.

I know of one formula that we commonly use for flow across orifice:

Flow = Flow Constant (K) x SQRT [(Differential Pressure x Inlet Pressure in abs.)/ (Sp.Gr x Abs. Temp)] --- (A)

But the construction team on site sent me below formula that calculates "Actual Quality velocity" - new word for me.

Actual Quality velocity = Density x DP across orifice x SQRT [(Design Temp./Actual pressure (abs)) x (Actual abs. Pressure/Design Pressure)] --- (B )

Help require is:
1- What does "Actual Quality Velocity" stands for??
2- How are DP type transmitters calibrated for "compensated flow" in field??

Edited by chemtan, 16 December 2009 - 12:22 AM.

[chemtan]

Below are the process conditions for measurement:

Operating Temp, Deg C :
Min/Max/Design: 17 / 60 / 160

Operating Pressure, KPA :
Min/Max/Design: 4813 / 5124 / 6895

Flow rate, Kg/hr :
Min/Max: 74640 / 22,4950

Edited by chemtan, 16 December 2009 - 02:11 AM.