Some customers have raised questions about the calibration of the acidity meter. When do I need a few calibrations? The accuracy of the acidity meter is required. The PH meter requires three points of calibration. Two points are not enough.

In general, how to choose the pH calibration range is related to the pH of the solution. If you are testing alkaline solutions for a long time, it is of course inappropriate to choose 7.0 and 4.0 points! Remember that when we used the previous application, we prepared 10.0. , 7.0, 4.0 calibration solution, routine selection of 7.0 and 4.0 (normally measured acidity), for the alkaline determination, select 7.0, 10.0 repeated calibration.

In fact, the third point of pH correction is mainly depends on your sample. As you said, there are many types of calibration solutions ranging from pH 1.68 to 12.46. Depending on the final pH range of the sample, the appropriate calibration solution should be selected. We usually use 4.00, 6.86, 9.18. If your sample is more alkaline, you need 9.18, 10.01, 12.46.

The calibration sequence is also different according to different instrument conditions. Some requirements are calibrated in sequence, while others are not required. The instrument will automatically recognize it. Please refer to the relevant instrument manual.

Regardless of the pH meter, the pH=7 point must be corrected, and the pH=7 should be corrected first when the point is corrected for two or more days.

Generally, two points can be used to meet the requirements. If the requirements are high, the third point is considered. Some instruments can be calibrated at three points, and there are modes available, which can be used directly. Some do not, generally use two points two-point proofreading, that is, proofreading twice.

Configure these calibration reagents as briefly described below:

1. pH 4.00 solution: Dissolve 10.12 g of potassium hydrogen stearate dihydrogenate in 1000 ml of high purity deionized water.

2. pH 6.86 solution: using GR 3.37 g of potassium dihydrogen phosphate, 3.533 g of GR dibasic phosphate, and dissolving the solution in 1000 ml of high purity deionized water.

3. pH 9.18 solution: Dissolve in 1000 ml of high purity deionized water with 3.80 g of GR borax.

Note: The water used to prepare the 2 and 3 solutions should be boiled for 15 to 30 minutes before the dissolved carbon dioxide is removed. Avoid contact with air during the cooling process to prevent carbon dioxide contamination.

Wheeled Hose Reel Cart

Wheeled Hose Reel Cart,Hose Cart With Wheels,Large Hose Reel Cart,Garden Hose Cart With Wheels

NINGBO QIKAI ENVIRONMENTAL TECHNOLOGY CO.,LTD , https://www.water-hose-reel.com