4 Tips for Maintaining pH Meters and Electrodes

Imagine you are using a ruler to measure in inches. There's one problem: the space claimed by the ruler is actually 6/8 of an inch. If you don't know, none of your measurements are accurate.

In the world of pH testing, the same idea still applies. In order to obtain accurate pH measurements in the water quality industry, you need to be sure that your pH meter and probes are calibrated against a standard buffer solution that serves as a baseline against which other solutions can be compared. If the pH meter and probe have not been calibrated, there is no way of knowing how accurate or reliable the measurement will be. By using standardized buffers with well-defined characteristics and testing them against your pH meter, the instrument will automatically adjust.

Failure to calibrate pH meters and probes can distort readings and damage equipment. Since the whole point of using these instruments is to get accurate measurements, you want to avoid these results. Follow these four tips to get trustworthy pH readings while extending the life of your equipment.

1. Learn How to Use Your Specific pH Meter

The calibration process for each pH meter is slightly different. First things first, read this first: Read the manual that came with your pH meter to make sure you know how to calibrate the device. Otherwise, you may end up thinking you've successfully calibrated your meter, only to find out the hard way that the readings are inaccurate or that the calibration data isn't saved properly.

2. Calibrate your pH meter frequently

In order to optimize the accuracy of your readings, you will need to periodically calibrate your meters to ensure they will work with the specific pH electrodes they are connected to. This is necessary as it prevents loss of performance due to normal wear and tear. For best results, calibrate the meter before first use, when using it for the first time after a while, each time a different electrode is connected to the meter, and before performing measurements in a new pH range. Professionally calibrated.

Worried that the calibration process might take a long time? Each calibration point can take up to 60 seconds to stabilize when using fresh buffer solution at room temperature.

3. Maintain electrodes

The electrodes attached to the pH meter are what actually measure the pH. Therefore, in the water quality industry, it cannot be overemphasized that you need to take care of your electrodes. Otherwise, they dry out and stop working. Your pH electrode needs to be kept moist so that the sensing portion of the electrode has constant ionic activity. We recommend adding a few drops of potassium chloride electrolyte to the protective cap to ensure that the electrode's glass membrane remains hydrated and does not dry out. Avoid storing the electrolyte in deionized or distilled water, which can damage the pH sensor in the electrode's glass membrane.

4. Use the proper pH buffer

If you're not sure about the pH of your buffer solution, it's difficult at best to calibrate pH meters and probes properly. For this, the importance cannot be overstated of using a pH buffer that has been tested and confirmed to have a specific pH value. Beyond that, you need to make sure that buffer solutions haven't expired and that they haven't been sitting in storage for long. Keep in mind that opened buffers with a high pH may expire well before their expiration date.