Common reasons inaccurate pH reading include:
- A dirty pH probe preventing function
- An uncalibrated meter
- Damage to the glass sensing bulb in the pH probe (cracks can be hard to see)
- Damage to other parts of the electrode like the cable
Try the following trouble shooting steps
Step 1
Inspect the probe for damage.
If you see damage, replace the probe.
Step 2
Complete a probe refresh process.
- Soak in MA9016 Cleaning Solution for 15-20 minutes
- Rinse
- Soak in MA9015 Storage Solution for 2-3 hours
- Rinse
- Follow the Calibration Procedure for your meter
- Retest your sample
You should see a fast response with a reading in the range that you expect.
If the readings are still slow and / or out of the expected range, replace the pH probe or the pH pen if the electrode is not replaceable.
Other tips
- Always use fresh solutions
- When calibrating, bracket the expected value. For example, if you are expecting a reading of 5 pH, use 4.01 pH and 7.01 pH calibration solutions.