Does pH electrode response change in time?
Yes, the response of the pH electrode should change periodically. Your pH electrode and pH buffers should be checked systematically. Please note that better quality pH electrodes have a full range response of 96-102%. Final advice: If the Slope response is out of range, clean the pH electrode. If cleaning does not return the pH slopes response to an acceptable range, replace the electrode. Contaminated buffers may slightly contribute to shifted pH values.
