ATI Q46D Dissolved Oxygen System Part 9 – System Maintenance
51
O&M Manual
Rev-N (4/21)
Part 9 – System Maintenance
9.1 General
The Q46D/60 Dissolved Oxygen 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.
9.2 Analyzer Maintenance
No unusual maintenance of the analyzer is required if installed according to the guidelines of this
operating manual. If the enclosure door is frequently opened and closed, it would be wise to
periodically inspect the enclosure sealing gasket for breaks or tears.
9.3 Sensor Maintenance
Sensor maintenance is required for accurate measurements. The primary requirement is simply
to keep the sensor membrane clean. The membrane is a polymer material that is resistant to
anything that will be encountered in water streams. However, deposits or biological growth can
form on the surface of the membrane, and these deposits will reduce the sensitivity to oxygen.
Normally, these coatings can be removed by simply wiping the membrane with a soft cloth or
paper towel.
Should a coating form on the membrane that does not wipe off, it is best to change the
membrane. Chemical cleaning may work as well, but a new membrane is a more reliable
solution. To change a membrane, follow the Sensor Assembly procedure in this manual. Do not
reuse the electrolyte from the sensor when changing a membrane. Always refill with fresh
electrolyte. The electrolyte is stable and does not have a limited shelf life.
Even if no buildup is apparent on the membrane, it should be changed on a regular schedule.
The recommended membrane change interval is every 6-12 months depending on application.
The actual membrane life is often in excess of one year, but periodic preventive maintenance will
simply avoid having to do service on an emergency basis.
While the sensor is disassembled for membrane changing, examine the condition of the o-rings
on both ends of the electrolyte canister. If the o-rings show any signs of damage, replace them
with new ones from the spare parts kit. It is good practice to change these o-rings once a year,
regardless of their condition.
9.31 Lead Anode Replacement
Galvanic D.O. sensors consume the lead electrode during normal operation. As oxygen
is measured, lead is converted to lead oxide, and after a period of time, the lead is
expended. The lead electrode in ATI's D.O. sensor cartridge can be easily replaced (part
# 04-0003), and replacement should be done automatically every 12 months.
The lead electrode is the thick lead wire wrapped around the sensor body. It is
connected through a stainless steel post with a nut and star washer. To change the lead
electrode, remove the nut and washer and unwrap the old lead. Loop the end of a new
To Next Page
Loading...
Need help?
General
