Question
What pH buffers can be used to calibrate the sensION™+ portable pH meters?
Summary
pH buffers that can be used to calibrate the sensION™+ portable pH meters
Answer
Unlike the sensION™+ benchtop pH meters, the sensION™+ portable pH meters only allow certain buffers to be used for calibration. The meters are set up to automatically recognize pH 2.00, 4.01, 7.00, 9.21, and 10.01. It is not possible to perform a multipoint calibration with any buffers other than the auto-recognized set.
The only other option would be to perform a manual calibration but this only allows for a single point calibration. Proceed with the following steps to perform the single point manual calibration:
The only other option would be to perform a manual calibration but this only allows for a single point calibration. Proceed with the following steps to perform the single point manual calibration:
- Unscrew the protector containing the appropriate electrolyte.
- Rinse the sensor with deionized water.
- Dip the sensor into the solution in which manual calibration is to be performed.
- Press the check mark key to take a reading in the buffer.
- After the meter stabilizes and provides a pH value, press the calibration
and check mark keys 
at the same time. The measured pH value should be displayed at the top of the screen, 'CAL' should be displayed in the middle, and 'NanCAL' should be displayed on the bottom. - Press the up and down arrow keys to adjust the measured value to the pH buffer value.
- Press the calibration key to save the adjustment. One should see 'CAL OK' display to confirm the calibration has been saved.