Water Quality Tester - Measurement of PH in Water Quality Testing

PH value generally refers to the hydrogen ion concentration index, which is the negative value of the common logarithm of the hydrogen ion concentration (activity) in aqueous solution, i.e. -lg[H+].PH is one of the most important physicochemical parameters of aqueous solution, where natural phenomena involving aqueous solution, chemical changes and production processes are related to PH. Therefore, in the field of industry, agriculture, medicine, environmental protection and scientific research need to measure PH, the determination has an important significance.

For the determination of PH, qualitative methods can be determined by using PH indicators and PH test paper, while quantitative PH measurements need to be carried out using a PH meter. Although the test of water quality PH value is very simple, but in the daily use of different testing equipment, the actual operation method is also different. The following will introduce you to 3 methods of testing water PH value, no matter which one you want to use, these methods can help you get accurate parameter results.

The measurement of PH in water quality testing includes preparation, calibration of the PH meter, measurement of the PH of the water sample, analysis of the results, and maintenance of the instrument. By following the correct procedure and precautions, an accurate PH value can be obtained so that the acidity or alkalinity of the water can be assessed and appropriate measures can be taken to improve water quality problems.

The following is a common method of PH measurement:

1. Preparation: Make sure that the instruments and reagents are in good condition before making PH measurements. Materials to be prepared include:

PH Meter: choose a high quality PH meter with high accuracy.

PH Electrode: Use a special glass electrode and avoid contact with air or strong acid or alkali solutions.

Calibration Solution: There are usually two types of calibration solutions, acidic and alkaline, each with a known pH value.

Water Sample: Obtain an appropriate amount of sample from the water source to be tested.

2. Calibrate the PH Meter: Before starting the actual measurement, the PH meter must be calibrated to obtain accurate results. Follow the steps below to calibrate:

Wash the PH meter electrode and rinse it well with pure water.

Immerse the PH meter electrode in the acidic and alkaline calibration solutions in turn and wait a few minutes until the reading stabilizes.

Adjust the calibration knob on the PH meter to match the pH value of the calibration solution.

Check other calibration parameters, such as temperature compensation, to make sure they are set correctly.

3. Measurement of water sample PH: After completing the calibration, you can start to measure the PH of the water sample to be tested. Follow the steps below:

Wash the PH meter electrode and rinse it with pure water.

Insert the PH meter electrode into the water sample to be tested, make sure the electrode is completely submerged in the liquid.

Wait a few minutes until the indication stabilizes and record the stable PH value.

If multiple measurements are required, remember to wash and rinse the electrode before each measurement.

4. Analysis of Results:

Once the PH value is obtained, the results can be analyzed and interpreted. The common PH range is 0 to 14, where 7 indicates neutral, less than 7 indicates acidic, and more than 7 indicates alkaline. Depending on the actual need, it is possible to further compare PH differences between different water samples or track changes in the same water source.

5. Instrument Maintenance:

Timely cleaning and maintenance of the PH meter and electrode is essential to ensure accurate measurements. After each use, care should be taken to wipe the electrode clean and store it in an appropriate protective solution. Perform calibration and maintenance operations regularly to ensure the accuracy and reliability of the instrument.