Industrial Scientific Oldham MX52, Commissioning, Operating And Maintenance Manual

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Adjust the detector sensitivity:
- Inject the calibration gas using the gas injection pipe (or a remote calibrating fixed
device) in the same conditions as those applicable for the synthetic air (zero adjustment).
When the measurement has stabilized (on the local display panel or on the detector internal
terminals (current measurement)), act on the detector’s internal sensitivity potentiometer (see the
manual for the detector concerned) in order to set the value (on the detector display panel)
corresponding to the concentration of the reference gas or the corresponding current (terminals).
(See the note and examples for case 1).
- Then, CONSECUTIVELY set the value of the standard gas on the MX52 display panel
by acting on the measuring channel sensitivity potentiometer (Item A, Fig. 27).
- Stop the injection of the standard gas, wait for the measurement to return to zero (on the
MX52 display panel). Then, press the “CALIBRATION” key (item C, Fig. 27). The
flashing yellow LED is extinguished and the “C” on the display panel disappears. The
measuring channel now operates normally and calibration has been completed.
5.4.
4-20 mA output adjustment for a measurement channel
Ø
4 mA adjustment
- for a zero display
- check
1
the 4 mA output current and adjust it if necessary using the 4 mA
potentiometer : see fig 27 rep B.
Ø
20 mA output adjustment
- following the measurement display and the following formula :
Maximum scale
I = 4mA (0-DIV) + 16 mA x Number of divisions set
100 DIVISIONS
- Check
1
the 4 mA output current and adjust it if necessary using the 20 mA
potentiometer : see fig 27 rep B
1
Current reading is possible by connecting directly the corresponding output current (see fig 12) a "continuous"
milliammeter.