Method 1: Mechanical cleaning
On sludge, slime, or other soft deposits, mechanical cleaning can be used. Clean with a soft brush and a beaker or bucket of water. General debris and non-tenacious deposits can be removed in this way. On hard scale, a standard flat screwdriver blade can be used to carefully scrape hard scale and other tenacious deposits off the reference junction. The IC Controls 642 open tip design also allows a screwdriver to carefully score and crack hard scale against the glass shaft, then carefully slide it up and off the pH glass tip without touching the pH glass. After mechanical cleaning, again check the sensor against a pH buffer. If the sensor is still not developing the proper pH reading in the buffer you can proceed to a second cleaning method.
Method 2: Chemical cleaning
Chemical cleaning is a bit more involved, so IC Controls has made available a Chemical Cleaning Kit (IC Controls P/N A1600054). This kit contains all required supplies along with a complete instruction sheet to enable you to complete a chemical cleaning on your sensors.