Rosemount 2081 pH - Hold Mode for Maintenance; Sensor Maintenance

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MODEL 2081 pH SECTION 5.0
START-UP AND CALIBRATION
5.6 HOLD MODE FOR MAINTENANCE.
Before performing maintenance of the sensor, or
buffer checks, the transmitter should be placed in
the "Hold" mode. This mode of operation maintains
the output current at the last process value. To initi-
ate "hold " mode:
1. Depress and hold both push buttons simultane-
ously until "Hold" is displayed on the screen.
2. Release both buttons.
a The "Hold" flag will flash, and
b. The display will show "Hold" every two sec-
onds to confirm the hold status.
To place the transmitter back into normal operation,
(remove from "Hold" mode)
1. Depress and hold both push buttons simulta-
neously until "Hold" is displayed on the screen.
2. Release both buttons.
a. The "Hold" flag will stop flashing.
b. The display will stop showing "Hold" every
two seconds.
c. The transmitter output current will return to
normal operation.
5.7 SENSOR MAINTENANCE.
Always calibrate after cleaning or repair of the pH
sensor.
Always place transmitter into the "Hold " mode of
operation while preforming any maintenance to the
sensor to avoid loss of process control.
Always return transmitter to normal operation after
installing the sensor back into the process.
NOTE
To clean the electrode, rinse with distilled
water or dilute acid/base, then gently dry
with a clean tissue. The electrode should
not be rubbed or abraded because this
increases the electrostatic forces and
thus the response time of the electrode,
and it also rapidly ages the delicate elec-
trode gel layer. If possible, the stirring or
flow velocity past the electrode should
be increased rather than rubbing or
brushing the electrode.
Also, see the appropriate sensor manual
for any additional instructions.