Metex 2200C Conductivity Analyzer/Controller - Manual (Page 23)

Model 2200C Page 21
a) Turn off the power to the instrument. Connect your DVM in parallel with the 0-5
Vdc output terminals on the power supply board.
b) Turn on the power. Enter the Utility Menu as described in 7.2.1.
c) Press CALL until the CONTROL RELAY SETPOINT LED illuminates, which is
"0-1 mA/ 0-5 Vdc output adjust, low" in the Utility Menu (See table in 7.2.2).
Use the arrow keys to make your DMM read 1.25V. Press ENTER twice to
confirm.
d) Press CALL and the CONTROL RELAY DEADBAND LED will illuminate, which
is "0-1 mA / 0-5 Vdc Output adjust, high" in the Utility Menu (See table in 7.2.2.)
Use the arrow keys to make your DMM read 3.75V. Press ENTER twice to
confirm.
e) Press RUN to return to on line or press CALL to proceed to another item in the
Utility Menu.
7.6 Adjust 4-20 mA Output
7.6.1 It may be desirable to fine tune the 4-20 mA isolated output to take into account the
characteristics of your particular loop. Before deciding that the adjustment is
necessary, be aware of the "Output High" and "Output Low" settings you may have
programmed as described in Section 5.4. The following method involves a high and
low calibration and requires the use of a Digital Multimeter (DMM). Proceed as
follows ignoring the instrument display.
a) Turn off the power to the instrument. Connect your DVM in series with the 4-20
mA output terminals on the power supply board.
b) Turn on the power. Enter the Utility Menu as described in 7.2.1.
c) Press CALL until the ALARM HIGH LED illuminates, which is "4-20 mA Output
adjust, low" in the Utility Menu (See table in 7.2.2.) Now use the arrow keys to
make your DMM read 8 mA. Press ENTER twice to confirm.
d) Press CALL and the ALARM LOW LED illuminates, which is "4-20 mA Output
adjust, high" in the Utility Menu (See table in 7.2.2). Now use the arrow keys to
make your DMM read 16 mA. Press ENTER twice to confirm.
e) Press RUN to return to on line or press MENU to proceed to another item in the
Utility Menu.