How to use a pH meter and precautions to take
Preparation before using ph meter
1, the use of PH meter before the first three steam water to clean the electrode, pay attention to the glass electrode do not touch the broken.
2,Preparation in the platform next to the PH meter put to the adjustment of the NAOH liquid and HCL liquid.
3, in the refrigerator out of the fixed PH liquid (PH = 7.0), put with the platform.
4, open the PH meter, adjust the PH value, press ︿ key to select the PH and CAL options, select the CAL item, adjust the insertion into the PH liquid (PH = 7.0), press the " " key to select the data value to 7.0, the appearance of a small octagonal can be.
5,Insert the glass electrode into the solution to be measured, and then put in another electrode, stir the liquid appropriately (Note: Do not touch the broken glass electrode).
6, PH meter electronic unit use must pay attention to the protection of the circuit, in the PH value is not measured, to short-circuit the input of the PH meter, in order to avoid damage to the PH meter.
7, PH meter glass electrode socket must be kept clean, clean and dry, can not be exposed to salt spray and acid mist and other harmful gases, while it is strictly prohibited glass electrode socket stained with any water solution to avoid PH meter high input impedance.
8, not to the PH value you need to be careful to add such as NAOH liquid and HCL liquid, (according to the different adjustment range can choose a different concentration of the adjustment of the liquid, the concentration of small hours can be added quickly, when the concentration is large to add slow).
9, when adding liquid, be careful not to exceed the required fixed volume.
Notes on the use of ph meter
1, in general, ph meter instrument in continuous use, to be calibrated once a day; generally within 24 hours of the instrument does not need to be calibrated.
2, before using the ph meter electrode to pull down the upper end of the rubber sleeve so that it reveals the upper end of the small hole.
3, the calibration of the buffer solution is generally used for the first time with pH = 6.86 solution, the second time with a buffer close to the pH value of the measured solution, such as the measured solution is acidic, the buffer should be selected pH = 4.00; such as the measured solution is alkaline when the buffer is selected pH = 9.18.
4, measurement, the introduction of the electrode wire should be kept stationary, otherwise it will cause measurement instability.
5, the electrode must not be immersed in distilled water, PH meter electrode used for new electrodes or long unused electrodes, the electrode must be soaked in distilled water for a few hours before use, so that the PH meter electrode asymmetric potential can be lowered to a stable level, thereby reducing the electrode's internal resistance.
6, PH meter in the PH value measurement, to ensure that the electrode bubble completely into the measured medium, so as to obtain more accurate measurement results.
7, PH meter use, to remove the rubber plug of the reference electrode pitting liquid addition port
