Panametrics DigitalFlow XMT868i, Руководство по обслуживанию

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DigitalFlow™ XMT868i Service Manual 23
Appendix B. Calibration and Testing with PanaView
B.4.1 Analog Outputs
Additional analog outputs may be added to the Model XMT868i by installing an appropriate option card in Slot 1. This
option card contains two or 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

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 this value to obtain the 0 mA point.
Prepare for calibration by inserting an ammeter in series with the load on Output A of the option card. See Figure 12
on page 20 to identify the OUT(+) and RTN(-) pins for Output A on terminal block J2.
2. Double-click on either Output A or Output B to open the Analog Output menu. (Output A will be used as an exam -
ple in this manual.)
IMPORTANT: The procedure for calibrating Output B is identical to that for calibrating Output A . However, be sure to
reconnect the ammeter on terminal block J2 . See Figure 4 on page 12 for the correct pin numbers.
3. Double-click on 4 milliamps to calibrate the low end of the output range.
4. Double-click on 4 mA UP or 4 mA DOWN to adjust the ammeter reading UP or DOWN, until a 4 mA reading is
achieved, or
Double-click on 4 mA Numeric Cal, and directly enter the mA reading in the right pane.
5. Once you have achieved a 4 mA reading, double-click on either 4 mA STORE to store the calibration, or on 4 mA
ABORT to exit the menu without storing the calibration.
Note: If the ammeter reading cannot be adjusted within 5.0  A of the 4 or 20 mA setting, contact the factory for
assistance.
6. PanaView returns to the Analog Output window. Double-click on 20 milliamps , and repeat the procedure in steps
3, 4 and 5 to calibrate the high end of the output range.
Note: Skip the following prompt, if linearity testing of the output will not be performed at this time.
7. Double-click on % Test to test the linearity of the currently selected analog output.
8. Check the ammeter reading at 50% output . Then, enter a different output (0-100%) and double-click on percent .
Check the ammeter reading at this setting and press [Exit Page] when done.
Table 8 on page 21 lists the expected ammeter readings at various % Full Scale settings, for both 4-20 mA and 0-20
mA scales. Refer to this table to verify the accuracy of the ammeter readings taken above. If the linearity test
readings are not within 5

A of the values listed in the table, check the accuracy and wiring of the ammeter. Then,
repeat the low and high end calibrations. If the analog output still does not pass the linearity test, contact the factory
for assistance.
Click [Exit Page] to return to the Slot 1 window and calibrate additional inputs/outputs, or click [Exit Page] again to
close the Calibration/Test menu.