Reference, Installation, and Operations Manual

Section 6: Meter operation

3-9000-743 Rev S

June 2013

 

 

 

Equation 6-5 Chord proportion calculation

 

 

Propchord =

Vchord

 

 

V------------------AvgWtd

 

 

 

where

 

 

 

Propchord

=

chord proportion (dimensionless)

Vchord

=

chord velocity (m/s) (FlowVelA ... FlowVelD)

VAvgWtd

=

average weighted gas flow velocity (m/s)

 

 

(AvgWtdFlowVel)

When the meter has operated for a user-specified number of consecutive batches without any chord failures, the meter updates each chord’s data values for the bin containing the chord velocity as shown in Equation 6-6and sets the bin’s “trained” indicator to TRUE. The PropUpdt- Batches data point, configurable via the Daniel MeterLink Edit/Compare Configuration screen, specifies the number of consecutive failure-free batches required for updating the bin data (range: [1, 1000], default: 24). The NumVals data point (that determines how quickly an average value changes) is also configurable via the Edit/Compare Configuration screen (range: [1, 1000], default: 10).

Equation 6-6 Updating chord proportion bin data values

AvgVelChordBinn + 1

=

(AvgVelChordBinn ⋅ (NumVals – 1)) + Vchord

-------------------------------------------------------------------------------------------------------------NumVals

AvgPropChordBinn + 1

=

(AvgPropChordBinn ⋅ (NumVals – 1)) + Propchord

---------------------------------------------------------------------------------------------------------------------------NumVals

where

 

 

 

 

 

AvgVelChordBin

n + 1

=

chord bin (n+1)st average velocity (m/s)

 

=

 

AvgVelChordBin

n

chord bin nth average velocity (m/s)

 

 

 

=

 

NumValsupdate factor data point (dimensionless) (NumVals)

Vchord

=

chord velocity (m/s) (FlowVelA ... FlowVelD)

AvgPropChordBin

n + 1

=

chord bin (n+1)st average proportion value

 

 

=

(dimensionless)

AvgPropChordBin

n

chord bin nth average proportion value (dimensionless)

 

 

 

=

 

Propchord

chord proportion (dimensionless)

Average weighted gas flow velocity

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