GE DigitalFlow GC868, Руководство по обслуживанию

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April 2008
1-2 Calibration
Calibrating the Analog
Outputs
Every Model GC868 flowmeter includes two built-in analog outputs
(A and B) at terminal block
I/O
, which is designated as
Slot 0
.
Additional analog outputs may be added to the Model GC868 by
installing an
Analog Outputs Option Card in one (or more) of the six
expansion slots. Each option card contains four analog outputs, which
are designated as A, B, C and D. Both the zero-point and full-scale
values for each output must be calibrated. After calibrating the
outputs, which have a resolution of 5.0
μ
A (0.03% full scale), their
linearity should be tested.
Note:
The zero point of the analog output may be set for either 0 mA
or 4 mA. However, the calibration procedure always uses the 4
mA point, as the meter will extrapolate from this value to
obtain the 0 mA point.
Prepare for the calibration procedure by connecting an ammeter to the
desired analog output of
Slot X
, as shown in Figure 1-1 below and
Figure 1-2 on page 1-3. Refer to Figure 1-6 on page 1-15.
Figure 1-1: Ammeter Connection (Output A)
Terminal Block I/O (Slot 0)
B
RTN
B
SIG
A
RTN
A
SIG
4 1
+
-
Ammeter