Extend the life of your electrode by following these hints on maintenance.
Using the correct electrode storage solution prevents electrode filling solution dilution and ensures minimum electrode response time.
If the readings become slow or drifty, clean the electrode per the manufacturer's instructions. Remember that excessive cleaning may impair electrode performance and shorten electrode life.
If using a refillable electrode, remove the fill hole cover during calibration and measurement to ensure a uniform flow of electrode filling solution. Cover the fill hole overnight and during storage.
The filling solution level must be higher than the sample level to maintain a uniform flow of filling solution. At least 1 inch above sample height is recommended.
Rinsing prevents contamination by carry-over on the electrodes. Rinse with deionized water or an aliquot of the buffer, standard or sample. Do not wipe the pH electrode glass bulb. Transfer of static charge onto the glass bulb will result in slow or drifty response.
Stir all buffers and samples at a uniform rate to obtain a representative sample measurement and improve electrode response time. Prevent heat transfer by using a piece of insulating material between the stir plate and beaker.
pH Buffers should be accurate and free of contamination. Keep the buffer or standard bottle tightly sealed. Do not re-use and ensure they are within the expiration date before use.
Calibrate at least once a day with 2 or 3 buffers that bracket the expected sample range. Choose pH buffers that are no more than 3 pH -units or no less than 1 pH unit apart.