Sensors are the eyes into a control system. When they are clean and functioning properly, they provide a clear picture about a system’s water chemistry and help optimize its operation. If a sensor becomes dirty or inaccurate it can cause you to lose control of a good system resulting in operational challenges that are time consuming and costly to correct. To do their job effectively they require periodic cleaning and maintenance. Below are some typical sensors and steps to clean dirt, oil and chemical deposits.
How do you know when it is time to clean your sensors?
After a new installation it is recommended that electrodes be cleaned after two weeks of service. After the initial cleaning you will need to do periodic checks to determine the fouling rate for the system being monitored and then set up a routine cleaning schedule. Below are some signs that indicate it is time to clean your sensors:
- Slow response readings
- Readings are inconsistent
- There is an increased need to recalibrate
- There is visible buildup on the sensor
How to clean your sensors
Below are steps to properly clean your sensors. You will need a soft bristle brush, squirt bottle, mild detergent, soft cloth, and possibly isopropyl alcohol or HCl. Before removing any of the sensors be sure to turn off chemical feed pumps or valves that are controlled by the sensor so that they are deactivated during the cleaning process. Always remember to recalibrate the sensor immediately after cleaning.
The type of coating determines the type of cleaning technique.
- Soft coatings: Remove coating using a squirt bottle and gently wiping with a soft, clean, non-abrasive paper or cloth. Mild detergent can be used if needed.
- Hard coatings: Remove coating using an appropriate solvent that is chemically compatible with the electrode. Use the least harsh chemical that will dissolve the coating in 1 or 2 minutes.
- Oily or organic coatings: remove with detergents or a solvent that is chemically compatible with the electrode.
Debris will accumulate on the conductivity sensor and need to be cleaned periodically.
- Soft coatings: scrub with a toothbrush or stiff bottle brush
- Oils: use detergent or isopropyl alcohol cleaner
- Calcium scale: use a mild acid to clean the scale buildup
Avoid hard abrasives and be sure to rinse the sensor thoroughly before returning to service.
• Remove chemical or biological fouling with mild detergent and a soft bristle brush, then rinse thoroughly.
• If additional cleaning is necessary, use a 10% HCl solution in place of the mild detergent. Note that HCl is a hazardous material and should be used only by qualified personnel.
Once you have established a maintenance routine, sensor cleaning is a quick and easy job. If you ever have questions about your equipment or maintenance please reach out to Watertech at firstname.lastname@example.org or 414-425-3339.
Sources: Walchem, IWAKI America