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O&M Manual
Rev-B (7/15)
Part 7 – System Maintenance
7.1
General
The PQ45P pH Monitoring System will generally provide unattended operation over long periods
of time. With proper care, the system should continue to provide measurements indefinitely. For
reliable operation, maintenance on the system must be done on a regular schedule. Keep in
mind that preventive maintenance on a regular schedule is much less troublesome than
emergency maintenance that always seems to come at the wrong time.
7.2
Analyzer Battery Replacement
No maintenance of the analyzer is required. All that’s required is to replace the C-Cell batteries
when they become discharged. The batteries are located inside the electronic unit. Loosen the 4
screws in the corners of the electronics and allow the front section to hinge down. A Velcro strap
holds the batteries in place. Carefully pull out the strap and then remove and replace the
batteries. Pay attention to battery polarity to insure proper operation. Use only high quality
batteries in this instrument. Use of poor quality batteries often results in battery acid leakage that
will damage the electronics.
If the system will not be used for a period of more than 30 days,
remove the batteries from the instrument to avoid possible damage.
7.3
Flow Cell Maintenance
The maintenance on the flow cell is simple cleaning. The flow cell is clear to make examination
of the condition of the sensor easier without interfering with operations. The flow cell may be
cleaned by wiping or by washing with detergents or dilute acids. Do not try to clean with solvents
as the acrylic may craze or crack.
Change the o-ring in the flow cell yearly or if any damage is observed. If insertion of the sensor
into the flow cell becomes difficult, use silicon grease to lubricate the o-rings that hold the sensor
in place. Use only enough grease to provide surface lubrication. Excess grease could foul the
sensor membrane.
