pH/ORP electrode cleaning

Coating of an electrode’s measuring surface can lead to erroneous readings including shortened span and slow response times. The type of coating determines the type of cleaning technique. Soft coatings can be removed by vigorous stirring, by use of a squirt bottle, or very carefully, by gently wiping with a soft, clean non-abrasive paper or cloth.

Hard coatings should be chemically removed. The chemical used to remove the coating should be the least harsh chemical that dissolves the coating in 1 or 2 minutes and does not attack the electrode’s materials of construction. Examples:

1. Calcium carbonate coating might be removed with 5% HCl (muriatic acid).

2. Oily or organic coatings are best removed with detergents or an appropriate solvent that does not attack the electrode’s materials of construction. For example, isopropyl alcohol might be used, but acetone should be avoided if the electrode’s body is made of CPVC.

Note: When using chemicals or solvents, care should be taken and appropriate eye, face, hand, body and/or respiratory protection should be used.

Never abrade or sand a pH electrode’s surface. However, the measuring surface of an ORP/REDOX electrode may be gently abraded by use of 600 grade wet silicon carbide paper, jewelers rouge or very fine steel wool.