Specific operation steps for correct use of acidity meter
Acidity meter, also called ph meter, is a commonly used instrument in the laboratory, mainly used to precisely measure the pH value of liquid medium (such as Mettler PH meter). So do you know how to use the acidity meter correctly? Lebe is now here to share with you how to use the acidity meter correctly.
In the daily operation of the laboratory, the first thing we need to do is to calibrate. Adjust the slope regulator of the acidity meter to 100%, and then adjust the temperature regulator to the temperature value according to the temperature of the solution to be tested. Then position and insert the combination electrode into the instrument.
Second, the more critical thing is positioning. Choose a buffer solution that is closest to the pH value of the sample, put the electrode into this buffer solution, and shake the beaker to make the solution uniform. Wait until the reading stabilizes to see this reading, which is the pH of the buffer solution. If high-precision measurement is required, two buffer solutions must be selected, that is, the pH value of the sample to be tested is between or close to the pH values of the two buffer solutions, and the pH can be read after the reading of the second buffer solution is stable. value, if it is unstable, you need to adjust the positioning regulator.
After that is the measurement. The pH-calibrated instrument can be used to determine the pH value of the sample. At this time, all regulators need to keep the original position after positioning. Then clean the electrode, insert the electrode into the beaker containing the sample to be tested, shake the beaker gently, and when the reading is stable, the pH value of the sample to be tested will be displayed. Here, one thing that needs special attention is that the glass electrode must be soaked in distilled water for more than a day and night before the first use. It should also be soaked in distilled water during normal use and must be cleaned before use. In addition, there are a few points that we need to pay attention to:
1) The glass electrode should not be in contact with strong water-absorbing solvents for too long, and should be operated as soon as possible when used in a strong alkali solution, and should be washed with water immediately after use;
2) Since the bulb film of the glass electrode is very thin, it cannot touch the glass and hard objects;
3) When the glass film is stained with oil, alcohol should be used first, then carbon tetrachloride or ether, and finally soaked in alcohol, and then washed with distilled water. Otherwise, when the solution containing protein is measured, the surface of the electrode will be polluted, which will lead to non-standard readings and large errors.
4) After the electrode is cleaned, it can only be blotted gently with filter paper, and do not wipe it with a fabric, which will cause static charge on the electrode and cause incorrect readings.
The correct way to use the acidity meter is to establish the maintenance of the instrument during use. Mettler acidity meter is easy to maintain and easy to operate is a good choice. Whether the instrument is well maintained or not determines the results obtained in the experiment. Therefore, we must pay attention to details when using laboratory equipment such as acidity meters. Using laboratory equipment is not as informal as life. Get good experimental results.
