Reference, Installation, and Operations Manual

Section 6: Meter operation

3-9000-743 Rev S

June 2013

 

 

 

The validity of the GC-read gas property data is readable via the AreGasPropertiesInvalidGC data point where TRUE(1) indicates invalid data and FALSE(0) indicates valid data. Refer to Section 6.5.5 for further information on how the data validity is determined.

“In-Use” gas property data

The “In-Use” gas property data is the actual data used by the meter for calculations.

The GasPropertiesSrcSel data point is used to select the gas property data source as either Fixed (0) or Live - GC (1). If the data source is Live - GC and the GC-read data is invalid, then the GasPropertiesSrcSelGCAlarm data point is used to select the data source as either Last good value (0) or Fixed value (1). When Last good value is selected, the “In-Use” gas property data is not updated with the invalid GC-read gas property data. When Fixed value is used, the “In-Use” gas property data is updated with the fixed gas property data.

The meter maps the appropriate input gas property data points (fixed or GC-reported as discussed above) to the corresponding “In-Use” data points (the HeatingValueInUse data point and the gas composition data points listed in the Table 6-9below).

Table 6-9 “In-Use” gas composition data points“In-Use” gas composition data points

N2InUse

CO2InUse

H2InUse

COInUse

MethaneInUse

EthaneInUse

PropaneInUse

IsoButaneInUse

NButaneInUse

IsoPentaneInUse

NPentaneInUse

NHexaneInUse

NHeptaneInUse

NOctaneInUse

NNonaneInUse

NDecaneInUse

H2SInUse

HeliumInUse

WaterInUse

OxygenInUse

ArgonInUse

Gas properties

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