How to choose the pH meter electrode
1. Type of electrode film: For the membrane electrode, different glass films should be selected according to the durability of the electrode, the applicable range of temperature, and the influence of sodium ion in a high-pH environment. ISFET electrodes are suitable for the measurement of solid substances such as foods.
2. Electrode shell: The glass shell has good corrosion resistance, anti-solubility and high temperature resistance exceeding 100°C. In comparison, the plastic housing electrode is not suitable for measurements above 80°C. Therefore, the electrodes of the glass case are suitable for the measurement of conventional high-precision pH, and the electrodes of the plastic case are good choices for rougher applications.
3. Reference electrode: The electrode can be filled to allow the reference electrolyte to be reused. The sealing electrode is usually filled with a colloid for the electrolyte carrier, and the electrode must be replaced when the colloid is contaminated. The reusability and electrical stability of the mercurous chloride reference electrode are slightly better than that of the Ag/AgCl reference electrode at room temperature and relatively stable temperature, but its use temperature cannot be higher than 80°C. It is suitable for clinical use. Detection, such as protein-containing samples, organic buffers, and high purity water measurements. Ag/AgCl electrodes have good temperature stability and are suitable for use in the range of -5 to 110°C.
4. Salt Bridge: The single-saline electrode is used in routine applications. The double-salt bridge electrode is suitable for the measurement of organic compounds, proteins, heavy metals, and interference components containing silver and sulfur.
5. Application: The economic compound electrode can be used for routine measurement in the laboratory and field. Plastic housing has good impact resistance. Open electrodes provide fast, stable response and long life. For special measurements, different electrode lengths and radii should be selected according to the situation. The life of electrodes that can be filled with electrolyte can be extended. It is suitable for measuring samples with a certain viscosity or low conductance samples.