GE DigitalFlo XGM868i, Руководство по обслуживанию

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Chapter 1. Calibration
2 DigitalFlow™ XGM868i Service Manual
1.3 Calibrating and Testing Analog Outputs
Every Model XGM868i flowmeter includes two built-in analog outputs (A and B) at terminal block
J1
, which is
designated as
Slot 0
. Additional analog outputs may be added to the Model XGM868i by installing an appropriate
option card in
Slot 1
. This option card contains two analog outputs, which are also designated as A and B.
Before beginning calibration, an ammeter must be connected to the desired analog output. Both the zero-point and
full-scale values for all of these outputs must be calibrated. After calibrating the outputs, which have a resolution of 5.0

A (0.03% full scale), their linearity should be tested.
Note: The zero point of the analog output may be set at either 0 mA or 4 mA. However, the calibration always uses
the 4 mA point, as the meter extrapolates this value to obtain the 0 mA point.
1.3.1 Preparing for Calibration
Prepare for calibration by inserting an ammeter in series with the load on the desired output. Refer to Figure 1 and
Figure 4 on page 12 to identify the
OUT(+)
and
RTN(-)
pins for the desired output.
Figure 1: Ammeter Connection (Output A)
Terminal Block J1 (Slot 0)
B
RTN
B
SIG
A
RTN
A
SIG
4 1
+ -
Ammeter
Load