YSI 5200 - Manual (Page 113)

YSI Incorporated 111 5200 Recirculating System Monitor
DO Sensor
Hex Key
Wrench
Set Screw
Probe Sensor Guard
Chemical Cleaning: Remove the membrane cap and soak the entire anode section in a 14% ammonium
hydroxide solution for 2 to 3 minutes, followed by a thorough rinsing with clean water. The anode should
then be thoroughly wiped with a wet paper towel to remove the residual layer from the anode.
Mechanical Cleaning: Sand off the dark layer from the silver anode with 400 grit wet/dry sandpaper.
Wrap the sandpaper around the anode and twist the sensor. Rinse the anode with clean water after
sanding, followed by wiping thoroughly with a wet paper towel.
NOTE: After cleaning, a new membrane cap must be installed. Refer to Section 4.6 Membrane Cap
Installation.
Turn the instrument on and allow the system to stabilize for at least 30 minutes. If, after several hours,
you are still unable to calibrate, contact your dealer or YSI Customer Service. Refer to Section 14
WARRANTY AND SERVICE INFORMATION.
Gold Cathode Cleaning
For correct sensor 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 and tool provided in the YSI 5238 Probe Reconditioning Kit.
Using the sanding paper provided in the YSI 5238 Probe Reconditioning Kit, wet 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. Rinse the cathode with clean water after sanding, followed by wiping thoroughly with a wet paper
towel. If the cathode remains tarnished, contact your dealer or YSI Customer Service. Refer to Section 14
WARRANTY AND SERVICE INFORMATION.
NOTE: After cleaning, a new membrane cap must be installed. Refer to Section 4.6 Membrane Cap
Installation.
11.4.2 DO Sensor Replacement
1. Remove the probe sensor guard.
CAUTION: Thoroughly dry the sensor so that no water enters the probe module sensor port
when the sensor is removed.
Figure 11-1 5562 Probe Module - DO Sensor Replacement