YSI 5000, Руководство по обслуживанию

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YSI Incorporated Model 5000/5100 Service Manual 22
9.2 5910 AND 5905 DISSOLVED OXYGEN PROBES
Probes that have been exposed to hydrogen sulfide or sulfur dioxide for extended periods may
cease operating in a normal mode. Output current will decrease and may become unstable. Visual
symptoms include blackening of the silver anode and/or discoloration of the gold cathode.
ELECTRODE CLEANING
5900 series probes should be cleaned only when erratic readings occur or after about every 500
hours of use (two months). Each cleaning removes material and reduces the life of the probe, so
excessive cleaning should be avoided.
GOLD CATHODE
For correct probe operation, the gold cathode must be textured properly. It can become tarnished
or plated with silver after extended use. The gold cathode can be cleaned by using the adhesive
backed sanding disc provided in the 5906 Membrane Kit. Stick the disc to a small flat object,
like a bottle cap, then sand the gold with a twisting motion about 3 times or until all silver
deposits are removed and the gold appears to have a matte finish. If the cathode remains
tarnished, return the probe for service.
5900 Series Sensor
Cathode
(Gold)
Temperature
Sensor
Anode
(Silver)
SILVER ANODE
It is normal for a dark layer of silver chloride to cover the silver anode. After prolonged use it
may become necessary to clean the anode. Soak the probe in a 14% ammonium hydroxide
solution for 2 to 3 minutes or overnight in a 3% ammonium hydroxide solution. Rinse with
deionized water, recharge with electrolyte, and install a new membrane.