Upgrading a Mark II to a Mark III

 

Reference, Installation, and Operations Manual

June 2013

 

3-9000-743 Rev S

 

Equation C-6 Conversion of the Mark II “A” Polynomial Coefficients

A0(MarkIII) = A0(MarkII)

 

A1(MarkIII) = A1

(MarkII)

BG

A2(MarkIII) = A2

(MarkII)

BG2

A3(MarkIII) = A3(MarkIII) BG3

Substituting Equation C-6into Equation C-4results in the following equation:

Equation C-7 Mark III Application of Converted Mark II “A” Polynomial Coefficients

vDryCal = A0(MarkII) + [(A1(MarkII) BG) ⋅ vAvgWtd] +

[(A2(MarkII) BG2) ⋅ v2AvgWtd] + [(A3(MarkII) BG3) ⋅ v3AvgWtd]

Inspection of Equation C-2and Equation C-7illustrates that the Mark II “A” polynomial coefficient conversion to Mark III “A” polynomial coefficients does indeed yield the same result as the Mark II.

Converting Mark II “BG” and Velocity Offset, Meter Factor

The Mark II British Gas Factor (BG) and Velocity Offset, Meter Factor are converted to equivalent Mark III dry-calibration “A” polynomial coefficients as shown in Equation C-8below. The equations are the same for calculating both the forward and reverse Mark III dry-calibration “A” polynomial coefficients.

Equation C-8 Conversion of the Mark II “A” Polynomial Coefficients

A0(MarkIII) = –(VelocityOffset MeterFactor)

A1(MarkIII) = MeterFactor BG

A2(MarkIII) = 0

A3(MarkIII) = 0

Substituting Equation C-8into Equation C-4results in the following equation:

Equation C-9 Mark III Application of Converted Mark II (Velocity Offset, Meter Factor)

vDryCal = – (VelocityOffset MeterFactor) + [(MeterFactor BG) ⋅ vAvgWtd]

=– (VelocityOffset MeterFactor) + (vAvgWtd BG MeterFactor)

=((vAvgWtd BG) – VelocityOffset) ⋅ MeterFactor

Inspection of Equation C-3and Equation C-9illustrates that the Mark II (Velocity Offset, Meter Factor) conversion to Mark III “A” polynomial coefficients does indeed yield the same result as the Mark II.

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Metrology - calibration equation parameters