YSI Pro-BOD - Manual (Page 8)

6
Silver Anode
It is normal for a dark layer of silver chloride to cover the silver
anode (for its location, see figure 2). 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.
The anode may also need a very light sanding with the supplied
sanding discs. Sand lightly in a helical fashion (down and
around), then rinse well with deionized water.
Cathode
(Gold)
Temperature
Sensor
Anode
(Silver)
Figure 2: 5905/5010/200-BOD/Pro-BOD Sensor