Upgrading a Mark II to a Mark III

Reference, Installation, and Operations Manual

June 2013

3-9000-743 Rev S

 

 

C.4.2 Metrology - calibration equation parameters

The Mark III calibration calculations are slightly different than those of the Mark II. The purpose of this section is to illustrate the differences and show how the Mark II calibration values are converted for use in the Mark III to achieve the same results.

Mark II Calibration

The Mark II calibration is comprised of three basic steps:

1.application of the “British Gas” (BG) Factor (see Equation C-1)

2.application of either the “A” polynomial coefficients (see Equation C-2) or the (Velocity Offset, Meter Factor) parameters (see Equation C-3)

3.application of the 10-point linearization (optional)

Equation C-1 Mark II Application of the British Gas Factor

vBG = BG vAvgWtd

Equation C-2 Mark II Application of the “A” Polynomial Coefficients

vDryCal = A0 + A1vBG + A2v2BG + A3v3BG

=(A0 + (A1 BG vAvgWtd) + (A2 BG2 vAvgWtd2) + (A3 BG3 vAvgWtd3))

Equation C-3 Mark II Application of the [VelOffset, MeterFactor]

vDryCal = (vBG VelOffset) ⋅ MeterFactor

=((vAvgWtd BG) – VelOffset) ⋅ MeterFactor

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Metrology - calibration equation parameters