Calibration
4-20
SVP Controller Operation Manual
Part No.: 44200004 - Revision 2
CPLp = Correction for effect of pressure on liquid (water)
= 1/[1-(0.0000032*Pp)]
WDz = Average of all WD’s
= [@sum (WDz Fill 1..WDz Fill5)]/n
WDzb = Volume of Prover at 60 deg F and 1 atm
= WDz/(CPSp * CPLp)
Gravimetric Water Draw Calculations
Gravimetric Water Draw technique is completed in accordance with API
4.9.4. Volume correction factors are based on API Manual of Petroleum
Measurement Standards API chapters,: 4.2, 4.9 and 12.2.4.
Corrections and representations:
Given:
Td
= Temperature of detector bar. (deg F)
Tp
= Temperature of prover. (deg F)
Ta
= Temperature of ambient air. (deg F)
Pp
= Pressure in prover. (psig)
Ww
= Weight of water. (grams)
h
= Elevation above sea level. (feet)
Dtw
= Density of test weights. (gm/cc)
Ga
= Area coefficient of expansion for flow tube. (API 12.2.4)
Gl
= Linear coefficient of expansion for detector. (API 12.2.4)
E
= Modulus of elasticity for flow tube material. (API 12.2 Appendix A)
WT
= Thickness of flow tube wall. (inches)
ID
= Diameter of flow tube. (inches)
Calculate:
Calculation of Air Density in USC Units:
ρ
A = 0.001223068*(1-(0.032 x h/1000))*(519.67/(Tf + 459.67))
Where:
ρ
A is the density of air (gm/cc) (Per API 4.9.4)
h is the elevation above sea level (ft)
Tf is the test temperature (°F)
Calculation for the Correction for Air Buoyancy on Weighing (CBW)
CBW= {[1-(0.0012/
ρ
TWr)]/[1- (0.0012/
ρ
TWf)]} * {[1-(
ρ
A/
ρ
TWf)]/
[1- (
ρ
A/
ρ
Ftp)]}
Where: CBW is the correction for air buoyancy on weighing,
ρ
TWr is the density of reference test weights (gm/cc),
ρ
TWf is the density of the field test weights (gm/cc) as per
certificate of traceability,
ρ
Ftp is the density of fluid at test temperature and test
pressure (gm/cc),
ρ
A is the density of dry air (gm/cc)