There are several types of calibration for industrial pH meter electrodes
Because the measurement of the electrode of the industrial ph meter is to convert the activity of hydrogen ions in the solution into a voltage value, and calculate the ph value, the purpose of buffer calibration is to measure the buffer solution of known concentration through the electrode, so as to obtain the voltage Value, and establish a curve of the relationship between voltage and ph value and store it inside the meter as the basis for measurement. There are three commonly used buffer solutions: 4.003, 6.86, and 9.182. In the process of debugging the instrument, use two standard solutions of 4.003 and 9.182 for calibration, and measure the buffer solution of 6.86 to see if it is accurate. In actual field application, it is necessary to determine which one or two to use to calibrate the meter according to the actual measured pH value of the sample water. If the tested water sample is acidic, that is, the pH value is less than 7, use two buffer solutions of 4.003 and 6.86 for calibration; if the tested water sample is alkaline, that is, the pH value is greater than 7, use two buffer solutions of 6.86 and 9.18 to calibrate. That is to say, the closer the pH value of the calibration solution is to the pH value of the measured water sample, the better.
For the ph measurement process, the most influential factor is the temperature. At different temperatures, even the same water sample will have different ph values. Therefore, various ph meters are equipped with temperature compensation circuits to eliminate this effect. The temperature electrodes used by the industrial ph meter of Beijing Times Newway to measure temperature are all made of platinum resistors. Platinum resistors have different resistance values at different temperatures, so the temperature of the water sample can be calculated by accurately measuring the resistance value of the temperature electrode. When calibrating, use the resistance box to input a specific resistance, and input the corresponding temperature value. The instrument will establish the functional relationship between temperature and resistance base, then when measuring, the resistance value transmitted from the temperature electrode can be calculated to obtain the temperature value.
