Pen Type PH Meter Price Determinant Acidity Test
1) Maintenance and precautions of pen type pH meter:
This pen-type pH meter has been calibrated before leaving the factory and can be used directly. It needs to be re-calibrated in the following cases:
It has been used (or placed) for a long time after calibration;
Electrodes are used particularly frequently;
The measurement accuracy requirements are relatively high;
When doing calibration, do not reuse the calibration buffer;
When the tip of the pen has white crystals, this is a normal phenomenon, please do not be nervous, you can soak it in clean water for a period of time;
Drop a few drops of preservation solution or calibration buffer into the pen holder, do not use distilled or pure water to soak or preserve the test pen;
There may be small air bubbles in the sensitive bulb of the glass electrode of the test pen, which will affect the normal measurement of the electrode. When using it, the electrode should be shaken to make the bubbles escape from the sensitive bulb;
Glass electrodes are easy to break, so be careful when using them;
If the displayed value is blurred or not displayed or the displayed value is much higher or lower than the real pH value of the solution, the battery should be replaced;
2) How to replace the battery of the pen type PH meter:
Gently pull out the black plate with the switch on the pen, do not break the wire, you can see 4 1.5V batteries, just pull out and replace;
Pay attention to the battery polarity and choose the same type of battery;
When the electrode is inserted into the solution to be tested or the calibration buffer, it should not exceed the maximum height marked on the test pen.
If the electrode is placed for a long time and the sensitive bulb is exposed to the air, the response will be slow and the display value will be unstable due to the dryness of the electrode. At this time, the electrode should be activated by immersing in distilled water for several hours;
To improve performance, insert the pH meter electrode into distilled water at least once a week for a few minutes;
Protein deposits (such as milk\cheese, etc.) should be immersed in pepsin and hydrochloric acid solution for elimination; this solution is prepared before use, after use, immerse the electrode in this solution for several hours, and then rinse it with clean water , followed by immersion in distilled water for several hours;
The grease film also affects the measurement of the sensitive bulb. Li removes this film, rinses the sensitive bulb with 75% alcohol solution, then wipes it dry with filter paper, rinses it with water, and then immerses it in distilled water for several hours;
3) Pen pH meter price pH calibration
Immerse the electrode of the test pen in the mixed phosphate standard buffer solution with a pH value of 6.86 (at 25°C), and shake it gently;
Use a small screwdriver to adjust the calibration potentiometer until the displayed value matches the pH value of the standard buffer solution at ambient temperature;
Insert the electrode into potassium hydrogen phthalate of pH 4.01 or borax standard buffer solution of pH 9.18;
The displayed value should be within the error tolerance range compared with the pH value of the buffer solution.
Pen-type PH meter price operation steps and methods
remove the protective case;
Clean the electrode of the pH meter with distilled water first, and use filter paper to absorb the moisture attached to the electrode;
Turn on the switch located on the battery compartment;
Insert the pH meter electrode into the liquid to be tested until the liquid is immersed slightly below the "immersion line". If conditions permit, the solution can be immersed to a position slightly higher than the "immersion line";
Stir the solution gently and read the displayed value after the value is stable;
After use, clean the electrode, turn off the switch, and put on the protective cover.
