BECS Technology BECSys Controller BECsys2

Slow response time and large offsets may indicate the electrode has become coated. The nature of the coating will dictate the type of cleaning technique that should be used.

Warning: You may lightly blot the water On a pH sensor tip on a paper towel, but never vigorously rub or wipe the pH bulb because this may scratch the delicate outer layer on the pH glass impairing its response.

Soft coatings, like bacterial films, are best removed using a squirt bottle or the water jet from a faucet.

If this is not successful, then gently wipe with a soft wet cloth.

For a more severe coating, first try a strong detergent (something similar to Dawn liquid detergent) and warm water, using a soft brush (like a toothbrush). Isopropyl alcohol on a Q-tip is another good choice. Rinse the measuring end in distilled water before reinstallation.

Greasy and oily coatings are best removed with a detergent solution or a solvent that will not attack the sensor body. Methanol and isopropyl alcohol are good choices for solvents. Acetone, MEK, THF, or trichloroethane will irreparably harm the electrode.

Hard coatings, like calcium or lime scale, are best removed with a solvent appropriate for the particular coating. A 5% solution of hydrochloric acid (HCl) would be a good choice for calcium scale. If unsure of the proper solvent to remove a hard mineral coating, then alternate between a 5% hydrochloric acid and a 4% sodium hydroxide (NaOH) for 10 minutes each. After treating the electrode with these strong acids or bases, rinse the electrode with water and soak it in a pH 4 buffer for at least 1/2 hour.

The platinum tip of an ORP sensor can be cleaned with an abrasive as a last resort. Gently scour the platinum with a 600 grit wet emery cloth, or preferably, a 1-3 micron alumina polishing powder. ;