3-24
3.3.2.4 Flow Coefficients
The ZERO, SPAN, and LIN values are coefficients to the formula
Flow = A + Bx + Cx
2
where A = zero coefficient
B = span coefficient
C = linearity coefficient
x = output of the A/D converter card.
These coefficients are automatically computed during flow calibration (section 4.2.4)
AVG is the amount of averaging applied to the displayed value. Averaging is applied with the
formula
New Value = {(Previous Value *AVG) + New Reading}/(AVG + 1)
An AVG of zero (0) effectively eliminates averaging. An AVG that is very large has a
correspondingly large averaging affect. Non-integer averaging amounts are allowable; however,
negative amounts should never be used. An AVG of approximately 10 is typical, while an AVG
of 1000 would be excessively high.
The date indicated at the bottom of the screen is the last date of calibration or the date of the
most recent editing of any of the listed values. The date shown may not be edited and is updated
automatically during calibration or when changing coefficients on this screen.
MASS FLOW RATE
Zero
[ 0
]
Span
[ 4E-04
]
Lin
[ 0
]
Avg
[ 10
]
Last Cal Date 03/14/10
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