After measuring the acidity meter, the core of electrode cleaning and maintenance is "thorough removal of residues+targeted decontamination+dry and sealed storage" to avoid contamination or damage to sensitive membranes. The specific steps are as follows:
1、 Basic cleaning: removing surface residues
Immediately rinse the electrode head (glass film and reference electrode interface) with distilled water or deionized water after measurement. Gently shake the electrode during rinsing to ensure that any residual water sample is removed.
If there is slight oil stains or organic matter adhering to the surface of the electrode, soak it in a 0.1mol/L hydrochloric acid solution for 1-2 minutes, and then rinse it clean with distilled water to avoid residual chemicals affecting subsequent measurements.
After cleaning, gently absorb the surface moisture with a clean soft tissue or non fiber cloth. Do not wipe the glass film with force to prevent scratching the sensitive layer.
2、 Targeted decontamination: dealing with stubborn pollution
Scaling/inorganic pollution (such as calcium carbonate, metal oxides): Soak in a 5% dilute nitric acid solution for 5-10 minutes, gently stir during the process, and then rinse repeatedly with distilled water until the pH value returns to neutral.
Protein/biological pollution (such as wastewater and biological sample measurement): Soak in a mixture of 1% gastric protease and 0.1mol/L hydrochloric acid for 30 minutes, then rinse with distilled water to decompose residual organic matter.
Oil/grease contamination: Quickly wipe the electrode surface with anhydrous ethanol or isopropanol, immediately rinse with distilled water to avoid prolonged alcohol contact with the glass film and aging.
3、 Maintenance and storage: maintain electrode activity
Short term storage (reuse within 1-7 days): Soak the electrode in a dedicated pH electrode protection solution (3mol/L potassium chloride solution), do not soak it in distilled water or pure water, otherwise it will cause dehydration and failure of the glass film.
Long term storage (more than 7 days): First, thoroughly clean according to the above method, absorb moisture, and then cover the electrode head with a sealing cap containing a small amount of protective liquid. Place it in a dry, cool, and non corrosive gas environment, avoiding direct sunlight and high temperature and humidity.
Regular activation: If the electrode is not used for a long time or the response slows down, soak it in a 0.1mol/L hydrochloric acid solution for 2 hours, then transfer it to a protective solution and soak overnight to restore the sensitivity of the glass film.
4、 Key taboos and precautions
Do not soak the electrode in strong acid or strong alkali solution for a long time to avoid corrosion of the glass film and reference electrode.
Do not collide the electrode with hard objects to prevent the glass film from breaking; The wiring terminals should be kept dry and clean to avoid short circuits caused by water contact.
The protective solution needs to be replaced regularly (recommended every 3 months). If the protective solution becomes cloudy or discolored, it should be replaced immediately to prevent electrode contamination.
If the electrode glass film cracks, fogges or cannot be calibrated, it is necessary to replace the new electrode in a timely manner to avoid affecting the measurement accuracy.