Emerson Daniel 3410 Series Operation Manual page 36

Measurement
January 2019
The sign of the energy rate indicates the flow direction: a positive value indicates flow in
the forward direction, a negative value indicates flow in the reverse direction.
The energy rate validity is indicated by the EnergyRateValidity data point TRUE(1)
indicates valid). The energy rate is valid if the base-condition volumetric flow rate is valid
(indicated by QBaseValidity where TRUE(1) indicates valid) and if the in-use gas properties
are valid (indicated by AreGasPropertiesInvalidInUse where FALSE(0) indicates valid).
The energy rate is accumulated into the corresponding direction energy total regardless of
the energy rate validity.
The forward and reverse direction energy 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, an energy total of 12345.750 MJ is stored as 12345 MJ for the integer portion
and 0.750 MJ as the fractional portion. Note that while the energy rate can be positive
(indicating forward flow) or negative (indicating reverse flow), the energy totals are always
positive values.
The non-volatile energy total data points are as listed in the table below:
Forward direction
Integer
PosEnergy
4.5.8 Mass rate and totals
The Daniel 3410 Series Gas Ultrasonic Flow Meter meter calculates the mass rate and mass
totals (forward and reverse).
These calculations requires that the flow-condition pressure and temperature are available
(either fixed or optional analog inputs,
(either fixed or optionally read from a GC,
are performed (internally by the meter or externally with the results written to the meter,
Configure Gas Chromatograph
The mass rate is calculated as shown in
Equation 4-14: Mass rate
MassRate = mass rate (kg/h) (MassRate)
Q
Flow
ρ
Flow
The sign of the mass rate indicates the flow direction: a positive value indicates flow in the
forward direction, a negative value indicates flow in the reverse direction.
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).
36
Fraction
PosEnergyfrac
parameters).
MassRate = Q
= flow-condition volumetric flow rate (m
= "in-use" flow-condition gas mass density (kg/m
Reverse direction
Integer
NegEnergy
Gas properties), the gas composition is available
Gas property data), and the AGA8 calculations
Mass rate
× ρ
Flow Flow
3
/h) (QFlow)
3
) (RhoMixFlow)
Operations manual
DAN-20057316
Fraction
NegEnergyFrac
Operations manual