Phidgets Forums

Hello
I have read the posts concerning ph calibration by 2 points but i do not understand how to make the correction, i use the equation PH = 7 - (2.5 - SensorValue / 200) / (0.257179 + 0.000941468 * Temperature)
With the first calibration point at 7.00ph (offset) I will try asymmetry, so I subtract it or add it to the ph value resulting from the equation (correct?)
The second point I do at 4 or 9ph and with the Nernst equation calculate the slope value but at this point I do not know where to enter the value in the formula to get the correct values

Do you have suggestions or other ways to get the result?
thanks

Hi,

Same question for me. As it is very simple to calibrate with a simple equation (example at ​
https://phidgets.wordpress.com/2014/05/ ... r-dummies/), doing the same with temperature compensation isn't described on the web.

Or the problem comes from our lacks in mathematics ... !

It will be pleasant if someone could help us here

Sincerely,

Hello mrcrabs
thanks for your indication the article is interesting
in the case of calibration I think refer to the temperature of 25 ° C and anyway the calibration solutions are stable at the temperature variation (they come in a few pts of pH)
I will try to find the solution and if yes, I will share it, if someone has any suggestions please post

thank you