Maintenance; Sensor Cleaning; Sensors Without Wiper Unit; Sensors With Wiper Unit - ABB 4690 User Manual

4690 Series
Turbidity systems

9 Maintenance

The servicing schedule in Table 9.1 is a guide only. Because the
turbidity systems are designed for a wide range of applications,
where the nature of the sample can vary considerably, it may be
necessary to amend the schedule to suit the particular
installation and sample conditions.
Task
Wiper blade replacement
Light source (EPA 180.1)
replacement
LED light source (ISO 7027)
replacement kit
Table 9.1 Suggested Maintenance Schedule

9.1 Sensor Cleaning

9.1.1 Sensors Without Wiper Unit

These sensors are normally used on clean water samples and,
under normal conditions, may require only manual monthly
cleaning of the flow chamber. However, if a high turbidity
breakthrough occurs, clean the flow chamber immediately to
ensure accurate readings.

9.1.2 Sensors With Wiper Unit

The required automatic cleaning frequency of the flow chamber
and optical windows of the sensors can be determined only by
plant experience. It is recommended that checks are made at
appropriate intervals.
34
Recommended Frequency
Quarterly
Annually
Every 5 years
9 Maintenance
IM/4690–EN Rev. A