Throughout the life of a pH electrode, you need to be sure you are getting maximum performance and accurate results.

 

Providing accurate pH results. Maintenance and cleaning of the pH electrode.

pH value is an important parameter for evaluating and controlling product quality. 

To determine an accurate and reproducible pH value, it is important:

• obtain the correct and accurate pH meter;
• choose an electrode for a specific substance and with the required measurement range (water, meat products, milk - for each task you need a special pH electrode);
• periodic calibration is required (for this, pH buffers are used) and verification of the electrode against standard samples - this is the only way you can be sure of the correct measurement result;
• take measurements at the same temperature (usually 20 - 25 °C). Remember that the pH value correlates with temperature and even if you have a very new instrument with temperature compensation, you should not neglect bringing the sample to the required temperature;
• during measurement, make sure that there are no air bubbles at the tip of the electrode;
• store the sensor in the recommended storage solution or 3M KCl in between measurements;
• store and maintain the pH electrode properly between measurements.

Learn more about pH, how to measure it and improve the accuracy of readings by clicking on the link.

pH sensor maintenance

Regular maintenance is essential to ensure optimum accuracy, stabilization time, and life for your pH sensor. Maintenance includes cleaning the electrode, storing between measurements and soaking the dry probe (e.g. after long-term storage).

Storing the electrode

Do not store the sensor in deionized water or low ionic strength samples. When the probe is not in use, place the storage cap (usually supplied with the electrode) with storage solution on top of the probe. Use only the storage solution specified by the manufacturer. Other solutions can contaminate the electrolyte through the open diaphragm of the reference electrode, impairing the performance and accuracy of the sensor.

Cleaning the electrode

Clean the probe regularly to remove debris and keep the reference electrode diaphragm open. Signs of contamination:

• Incorrect or abnormal readings
• Slow stabilization
• Calibration errors
• Sample material remains on the sensor

For cleaning pH electrodes, the manufacturer HACH has a convenient range of special solutions that can be selected depending on the type of contaminant.

Note that probes with an open reference junction can become permanently damaged if the reference junction is soaked for a long time in a cleaning solution. Make sure to soak the probe below the reference junction only.

• General contamination: it is recommended to use a cleaning solution intended for regular maintenance, the active ingredient of which is KATHON™ CG, DECONEX®️ 11. Place probe tip for at least 12 - 16 hours. More about the solution ->
• Minerals: with this type of contamination, a solution is used to clean the electrodes from mineral / inorganic compounds, the active component of which is phosphoric acid (~ 10%). Place the probe tip for 10 - 15 minutes. More details ->
• Fats, greases and oils: in this case, the active component of the solution for cleaning the pH sensor will be KATHON ™ CG, TRITON®️ X. Soak time should not exceed 2 hours. Follow link to learn more ->
• Proteins: it is necessary to use a solution for cleaning from protein / organic contaminants, the active component of which is pepsin in HCl. Place probe tip for not more than 3 hours. Detailed description of the solution ->
• Wastewater and organic compounds: For this type of contamination, Hach recommends the use of a high potency solution in which sodium hypochlorite is the active ingredient. Soak time is only 5 - 10 minutes. Go to the page with the description of the solution ->

Follow the link to select a pH electrode for your application. If you cannot make a choice, e-mail or call us, the specialists of AquaAnalytics will help you choose a sensor for determining pH and provide recommendations for it's maintenance to ensure accurate results and a long service life.

Representative office in Russia: +7 (495) 201-53-02 info@aquaanalytics.ru

Representative office in Uzbekistan: +998 (90) 174-57-84 info@aquaanalytics-tekhnika.ru