Reference, Installation, and Operations Manual

Section 6: Meter operation

3-9000-743 Rev S

June 2013

 

 

 

The mass rate validity is indicated by the MassRateValidity data point (TRUE(1) indicates valid). The mass rate is valid if the flow-condition volumetric flow rate is valid (indicated by QFlowValidity where TRUE(1) indicates valid) and if the AGA8 flow-condition calculation is valid (indicated by AGA8FlowCalcValidity where TRUE(1) indicates valid).

The mass rate is accumulated into the corresponding direction mass total regardless of the mass rate validity.

The forward and reverse direction mass totals are each stored in non-volatile memory as a data pair: a 64-bit unsigned integer portion and a 32-bit floating point fractional portion. For example, a mass total of 12345.750 kg is stored as 12345 kg for the integer portion and

0.750 kg as the fractional portion. Note that while the mass rate can be positive (indicating forward flow) or negative (indicating reverse flow), the mass totals are always positive values.

The non-volatile mass total data points are as listed in the table below:Table 6-5 Mass Total Data Points

 

Forward direction

 

Reverse direction

Integer

Fraction

Integer

Fraction

 

 

 

 

PosMassPosMassFracNegMassNegMassFrac

 

 

 

 

6.1.14Seniorsonic flow characterizations

For Daniel Mark III Ultrasonic Gas Flow Meter SeniorSonic meters only, the following flow characterizations are calculated/estimated: symmetry, cross-flow, chord turbulence, profile factor, and swirl angle. Alarm limits are provided for the chord turbulence and swirl angle values.

Symmetry

Symmetry is a dimensionless measure of the flow symmetry comparing the upper chords to the lower chords and is readable via the Symmetry data point. Ideally the Symmetry should be 1.0.

Cross-flow

Cross-flow is a dimensionless measure of the flow symmetry comparing the chords on one side of the meter to the chords on the other side. It is readable via the CrossFlow data point. Ideally the Cross-flow should be 1.0.

Chord turbulence

Chord Turbulence is a estimate of the turbulence (percentage) at a chord location. A value is calculated for each active chord and is readable via the TurbulenceA, TurbulenceB, TurbulenceC, or TurbulenceD data points. A value of 0% indicates no appreciable turbulence.

Seniorsonic flow characterizations

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