Walchem WCT400 Series Instruction Manual

Walchem WCT400 Series Instruction Manual Manual pdf 39 page image

366.0 MAINTENANCEThe WCT controller itself requires very little maintenance. Wipe with a damp cloth. Do not spray downthe controller unless the enclosure door is closed and latched.6.1 Electrode CleaningNOTE: The controller must be recalibrated after cleaning the electrode.FrequencyThe electrode should be cleaned periodically. The frequency required will vary by installation. In a newinstallation, it is recommended that the electrode be cleaned after two weeks of service. To determinehow often the electrode must be cleaned, follow the procedure below.1. Read and record the conductivity.2. Remove, clean and replace the conductivity electrode.3. Read conductivity and compare with the reading in step 1 above.If the variance in readings is greater than 5%, increase the frequency of electrode cleaning. If there isless than 5% change in the reading, the electrode was not dirty and can be cleaned less often.Cleaning ProcedureThe electrode can normally be cleaned using a cloth or paper towel and a mild detergent. If coated withscale, clean with a dilute (5%) hydrochloric acid solution. Occasionally a electrode may become coatedwith various substances that require a more vigorous cleaning procedure. Usually the coating will bevisible, but not always. To clean a coated electrode, use fine grit abrasive, such as emery paper. Lay thepaper on a flat surface and move the electrode in a back and forth motion. The electrode should becleaned parallel to the carbon electrodes, not perpendicular.Figure 22 Cleaning the ElectrodeCLEAN INTHIS DIRECTION