Calibration method for Yokogawa FLXA402PH meter

The calibration method for the Yokogawa FLXA402PH meter is generally two-point or three-point calibration. The specific steps are as follows: 1. First, clean the electrodes with pure water, then insert them into the first buffer (such as pH=7.00). Start the stirrer on the surface of the liquid and move the electrodes around until the readings stabilize. 2. Find the calibration option on the host and follow the prompts to proceed. Set the displayed value to the pH of the buffer to perform the first calibration point. 3. After cleaning the electrode, insert it into the second buffer (such as pH=4.00 or 10.00) and continue stirring until the reading stabilizes. 4. Perform the second calibration on the host using the same method; remember to set the displayed value to the pH of this buffer. 5. If three-point calibration is required, then the third buffer (e.g., pH=9.18) is added, and the above steps are repeated. After calibration, wash the electrode with pure water, and then insert it into the sample solution for measurement. These are just general calibration steps; as there may be differences among specific devices, it is recommended that you consult the device’s manual or contact the manufacturer’s technical staff for guidance. .

The instructions can be downloaded from Yokogawa Electric’s official website, and the pH calibration procedures are generally similar for instruments of different manufacturers. What was mentioned above refers to the calibration methods used in laboratories; the basic steps for calibrating online analyzers are similar, but there are significant differences in the types of containers used and the amounts of reagents required. It is best for the operator to prepare some suitable containers on their own. It’s better to download the manual and learn *it first.

Thank you for your detailed explanation; many thanks

I prepared solutions of concentrations 4 and 7, and carried out two-point calibration. The display on this instrument makes it relatively easy to use; the calibration method is similar to that of the Mettler instrument I used before. The results of the calibration were a zero point of 20 mv and a slope of 86% – is that acceptable?

The slope is a bit off; this could be due to the electrode having been in use for a long time, or it might be necessary to replenish the potassium chloride reference solution for the reference electrode (if it’s a type of electrode that allows for such replenishment). If there is a spare electrode available, it can be used as a replacement. Electrodes are consumables. Are you still using the Yokogawa pH8 series electrodes?

I didn’t pay attention to the model of the probe at that time; it’s been in use for two years now