urgent! PH detection problem
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Now I have purchased a HACH PH meter, and the transmitter signal is: P53, the signal of the probe is: The PD1P1 differential probe was calibrated with standard solutions (PH4, PH7, PH9, PH13) before use, but when the pH meter was placed around PH13, the temperature: In a turbid solution containing magnesium hydroxide at about 60 degrees, the pH shows normal in the first 5S, and then changes between 7-9, which is 5-3 points different from the actual pH. Please ask the experts why.
Temperature has some effect on pH, but not significantly. You use 4 points for calibration. Personally, I think you should try using two points. Just mark 4 and 13, and there is no need to mark 7 and 9.
Tried it, but it doesn't work. Could you please think of a solution?
I think it has something to do with the temperature. You can test it again when the temperature of the item to be tested is low.
If it still doesn't work, you can only try changing the probe. You can also check whether the parameters set by the transmitter are correct.
The probe is new, and what I said above is that it is related to temperature, which is correct, but the meter has temperature compensation. The parameters are correct. After the transmitter was connected to the ground yesterday, the meter display error is not as small as before, but now the display fluctuates greatly, and it is about 2 points different from the actual PH. Please help me solve this problem, thank you.
Use PH=7 to calibrate the zero point, and then use the PH=4 standard liquid to calibrate the span point. If it doesn't work, hang up the 375 and use HART to enter the modification.
We don’t have a 375 handheld terminal in our factory, what should we do?
The poster's pH 13 liquid should contain other strong bases besides magnesium hydroxide, and there may be other things containing low-priced sulfides, right? If you guessed it correctly, you are using it to monitor wet desulfurization. It's not a temperature problem, it may be that there are sediments or deposits that affect the normal use of the pH electrode. Can you send me your specific situation and tell me the dealer who sold you the meter, and I can probably help you solve it.