Er1 will usually appear on the screen when users dip the probe into the wrong calibration solutions. For example, for pH calibration, the 1st point calibration must be 7.00 pH. If users dip into 4.00 or 10.01 for the 1st point calibration, Er1 will appear to remind you that it's not the correct calibration solution. If you are pretty sure you are dipping into the correct solution, but the Err1 still comes up, it could be caused by either of the following reasons:
- The calibration solution is contaminated or expired, thus not holding a correct standard value. Users need to replace new calibration solutions.
- After 1st point calibration, you turned the meter off and turn it back on for the 2nd point calibration. In that case, you need to start with 7.00 pH again, and then 4.00 or 10.01. Therefore, a good practice would be to do the 2nd point calibration right after the 1st point (7.00 pH) without turning off the meter.
- The pH probe of the meter loses its sensitivity due to long-time use or long-time dry storage. To solve this problem, soak the pH probe in the storage solution overnight, and then do the calibration again.
- Check if there is a small air bubble inside the glass bulb sensor. If you find it, simply shake the meter several times until the air bubble disappears. The existence of the air bubble inside the glass bulb will cause significant inaccuracy to the measurements.
If you have confirmed that it's none of the above reasons, try setting the meter back to factory default (refer to your instruction manual), and then perform the calibration again starting from pH 7.00. After that, if Er1 still comes up, it's possible that the pH probe of the meter is not working properly. Users can contact us or the retalier for return or replacement service.
Er2 will come up if the user presses the CAL button before the reading is fully stablized (smiley face comes up and stays on) in calibration mode. To solve this, just have a little more patience for the smiley face to come up and stay on the screen before pressing the CAL button to finish the calibration.