DH Instruments GFS2102, Operation And Maintenance Manual, Page: 166 / 206

GFS2102™ OPERATION AND MAINTENANCE MANUAL
© 2007 DH Instruments, a Fluke Company Page 150
VARIABLE DESCRIPTION
Q
DUT
Current DUT final output.
Q
f Re
Current reference final output.
Q
DUTspan
DUT span as determined by the difference between the
maximum and minimum final output values in the DUT Definition.
E
DUTFS %
DUT percent of full scale error.
E
Rdg %
DUT percent of reading error.
Q
Se
Test target in DUT final output unit.
Set DUTFS
E
_ %
DUT percent of full scale set point error.
Set Rdg
E
_ %
DUT percent of reading set point error.
5.7.3 TOLERANCE
The determination of whether a point is in or out of tolerance depends on the type of tolerance
selected, and the DUT and reference flow. Tolerance values may be specified in multiple
units (see 5.5.3.5).
GFS Tools first determines the tolerance value in DUT final output unit
and then compares the value to the current DUT error to determine if the error is smaller (in)
or larger (out) than the tolerance. When the DUT tolerance selection is (%D
%Reading) the tolerance is the sum of the two values. If the selection is %DUTspan or
%Reading, the tolerance used is the greater of the two values. Tolerances that are defined in
DUT final output, set, or output units are also compared directly in the test unit of measure.
DUTspan
DUTspan
DUTspan
Q
T
QT
× =
100
%
%
QT
T
Q
reading
reading
f %
%
Re
= ×
100
VARIABLE DESCRIPTION
T
DUTspan %
%DUTFS tolerance value defined in the DUT definition.
Q
DUTspan
DUT span as determined by the difference between the maximum
and minimum final output values in the DUT Definition.
DUTspan
QT
%
Maximum allowable( DUT – reference) deviation based on a
%DUTFS tolerance.
Q
f Re
Current reference final output.
T
reading %
%Reading tolerance value defined in the DUT definition.
QT
reading %
Maximum allowable (DUT – reference) deviation based on a
%Reading tolerance.
5.7.4 AUTOZERO CORRECTION
AutoZero is used to correct the balance for drift over time. The procedure is to first measure
the reference mass in the AMH-GFS2102 just after zeroing the balance and before starting a
flow accumulation. This value and all ambient conditions are stored. At a later time during
or after accumulation, the AMH is used to lower the reference mass again. The offset from