Measurement points of Best ph meter digital

The integrity of the Best ph meter digital electrodes should be checked before proceeding. Calomel electrode. Since the composite electrode is widely used, the following mainly discusses the composite electrode.

There are mainly two types of composite electrodes used in the laboratory, the fully enclosed type and the non-enclosed type. The fully enclosed type is relatively rare, mainly produced by foreign companies. Before using the composite electrode, first check whether the glass bulb is cracked or broken. If not, when two-point calibration is performed with pH buffer solution, if the positioning and slope buttons can be adjusted to the corresponding pH value, it is generally considered to be usable. Otherwise, press Use the instructions for electrode activation.

The activation method is to soak in 4% hydrogen fluoride solution for about 3 to 5 s, take out and rinse with distilled water, then soak in 0.1mol/L hydrochloric acid solution for several hours, rinse with distilled water, and then calibrate, that is, use pH value Position it for the buffer solution of 6.86 (25°C), after the adjustment, choose another pH buffer solution to adjust the slope. If it cannot be adjusted, the electrode needs to be replaced.

For non-sealed compound electrodes, an external reference solution, ie 3 mol/L potassium chloride solution, must be added. Therefore, it is necessary to check whether the potassium chloride solution in the electrode is more than 1/3. If not, add 3 mol/L potassium chloride solution. Potassium chloride solution. If the potassium chloride solution exceeds the position of the small hole, shake off the excess potassium chloride solution so that the solution is below the small hole, and check whether there are air bubbles in the solution. If there are air bubbles, flick the electrode to remove the air bubbles completely.

The above are the measurement points of Best ph meter digital, do you understand?