Last Updated10th of January, 2012
- Inspect sensor in bright light for cracks or flaws.
- Place 4.0 standard solution on sensor and attempt reading. Failed sensors generally cannot calibrate to the pH 4 solution. If so replace sensor.
- Condition sensor. Cover sensor with either standard solution and soak for 15 minutes. Rinse and attempt calibration.
- Make sure the drop covers the electrode and reference junction, or else sensor may be worn out.