Why does my pH electrode need to be hydrated?

Hydration of your pH sensing glass and the junction is key to accurate measurements.

All glass electrodes have a bulb and reference junction that must be kept hydrated. pH glass is unique as it forms a gel layer when properly hydrated which interacts with your sample and buffers. As an electrode hydrates their behavior shifts - therefore it is important to start and end calibrations and measurements with a hydrated electrode. 

Hydrating the junction ensures a connection between the internal electrolyte and the sample. Without this connection, the electrode can be slow to respond and have poor stability.

To minimize junction clogging and ensure fast response time, always keep the glass bulb and the junction of your pH electrode clean and hydrated.