ADS Environmental Services Model 4000 530017 A0 - Manual (Page 91)

Maintenance and Troubleshooting 5-5
Checking the Sensors
Perform the following sensor inspections during regular site visits:
Verify that the installation ring or bands are secure and clear of
debris.
Clean the face of the ultrasonic sensor gently with a soft brush
saturated with rubbing alcohol, and wipe the sensor with a
clean, moist cloth.
Verify that the face of the ultrasonic depth sensor is
horizontally level with the flow. Reposition, if necessary,
according to the procedures in Chapter 3.
Scrub the pressure sensor and face of the velocity sensor with a
soft brush saturated with rubbing alcohol.
Confirm that all sensor cables are neatly arranged, securely
fastened, and free of debris, cuts, and breaks that may affect
performance. Replace sensors that exhibit damaged cables.
Replace the desiccant in the pressure depth sensor's dryer tube
on a regular basis. Make sure the desiccant is still blue. Pink
desiccant indicates that it will no longer absorb moisture. If it
appears pink upon inspection, replace the desiccant
immediately in the following way:
Unscrew the middle of the dryer assembly.
Remove and save the used desiccant.
Refill the dryer tube with new desiccant.
Monitor pressure depth sensor performance for a while to
ensure no damage to the sensor electronics has occurred.
Note: Replacing desiccant quarterly may be sufficient;
however, replace it more frequently when necessary.