Using temperature compensation function to reduce measurement error
Because the change of electrode potential is different at different temperatures, pHS-3B-S pH meter is equipped with automatic and manual temperature compensation devices to adapt to the measurement of pH value under various temperature conditions. Before measurement, it is necessary to check the position of the temperature compensation switch on the back panel of the pH meter. If the automatic temperature compensation function is adopted, it must be set to the "automatic gear" position, and if the manual temperature compensation method is adopted, it must be set to the "manual gear" position.
The temperature compensation on pHS-3B-S pH meter only compensates the slope term of the electrode. Therefore, in order to get accurate measurement results, the measured precipitation sample and the standard buffer solution should be measured at the same and constant temperature as far as possible.
In order to reduce the measurement error of pH value caused by temperature, the temperature probe should be calibrated once a month, and it should also be calibrated after the installation and maintenance of the instrument, and the difference between the temperature value of the temperature probe and the standard temperature should not be greater than 0.5℃.
In order to reduce the measurement error of pH value of precipitation samples, observers should pay special attention to the process of temperature balance between the measured precipitation samples from collection to entering the laboratory and the standard solution, and cover the upper mouth of the beaker containing precipitation samples with clean watch glasses to prevent dust from falling, polluting the measured precipitation samples and causing errors in the measurement results.
4 the correct maintenance and maintenance of the instrument
PHS-3B-S pH meter has a high input impedance, and the use environment often comes into contact with chemicals. In order to ensure the normal use of the instrument, it is necessary for observers to maintain and maintain it correctly and reasonably, so as to keep the equipment in good and excellent technical condition all the time, thus reducing the measurement error.
