Five sections let you thoroughly understand the pH meter
The PH meter is an important tool for measuring and reacting the pH of the solution. There are various models and products of the PH meter, and there are two display modes: pointer display and digital display. However, no matter how the type of the PH meter changes, its working principle is the same. Likewise, its body is a precision potentiometer.
Electrode Composition Form in Potentiometric System
The composition of the pH electrode and the reference electrode in the potentiometric system:
1. Monomer pH electrode + reference electrode (pH electrode and reference electrode are separated, a total of two electrodes)
2. Composite pH electrode (pH electrode and reference electrode are combined on one electrode)
Potential difference of pH meter
Calibration of the pH meter uses a pH standard solution that conforms to JIS standards. pH standard solutions include oxalate (1.68pH), phthalate (4.01pH), neutral phosphate (6.86pH), phosphate (7.41pH), borate (9.18pH), carbonate (10.01pH ).
How to use the pH meter (steps)
Preparations before use of the pH meter
1. Clean the electrode with triple distilled water before using the pH meter, and be careful not to break the glass electrode.
2. Prepare to put NaOH solution and HCl solution for adjustment next to the platform pH meter.
3. Take out the constant pH solution (pH=7.0) in the refrigerator and put it on the platform.
4. Turn on the pH meter, adjust the pH value, press the ︿﹀ key to select the pH and CAL options, select the CAL item, adjust and insert it into the pH solution (pH=7.0), press the "" key to select the data value to 7.0, A small octopus can appear.
5. Insert the glass electrode into the solution to be tested, then put another electrode, and stir the liquid properly (note: do not break the glass electrode).
6. The electronic unit of the pH meter must pay attention to the protection of the circuit. When the pH value is not measured, the input of the pH meter should be short-circuited to avoid damage to the pH meter.
7. The glass electrode socket of the pH meter must be kept clean, clean and dry, and must not be exposed to harmful gases such as salt spray and acid fog. At the same time, it is strictly forbidden to have any aqueous solution on the glass electrode socket to avoid high input impedance of the pH meter.
8. Be careful to add NaOH solution and HCl solution when the pH value you need is not reached.
9. Be careful not to exceed the required fixed volume when adding liquid.
