pH and ORP Measurement Guide
Improve pH and ORP measurement through correct calibration, electrode conditioning, sample handling and interpretation.
Practical guidance
pH electrodes require hydration and should not normally be stored dry. Use two or more pH buffers that bracket the expected sample. Rinse between standards, blot gently and wait for stability. ORP is a relative electrochemical measurement and should be interpreted with process chemistry, reference electrode condition and temperature in mind. Clean coated junctions and replace electrodes that are slow or unstable.
Recommended routine
- Review the product manual and required standards.
- Inspect the instrument, cables and sensor condition.
- Calibrate at suitable points using fresh standards.
- Rinse and condition the sensor before measuring.
- Allow the reading to stabilise without contaminating the sample.
- Record the result together with temperature and calibration status.
- Clean and store the sensor correctly after use.
Frequently asked questions
How often should an instrument be calibrated?
Calibration frequency depends on sensor stability, application risk, sample type and quality procedure. Critical measurements may require calibration before each batch or shift.
Can the same sensor be used for every sample?
No. Sensor material, range, temperature and chemical compatibility must match the sample and application.
When should a reading be confirmed?
Confirm readings that are unexpected, safety-critical, near a specification limit or inconsistent with process conditions.