pH measurement and Temperature compensation question
anonymous 2018-07-05 09:52:52 4005 Views4 Replies In the documentation provided, Looking at the steps of using the pH meter(SEN0161), At number three
(3)Put the pH electrode into the standard solution whose pH value is 7.00，or directly shorted the input of the BNC connector.Open the serial monitor of the Arduino IDE,you can see the pH value printed on it,and the error does not exceed 0.3. Record the pH value printed,then compared with 7.00, and the difference should be changed into the "Offset" in the sample code. For example,the pH value printed is 6.88,so the difference is 0.12.You should change the "# define Offset 0.00" into "# define Offset 0.12" in your program.
Is there a problem if the measured value exceeds 0.3 and the offset value is adjusted too much?
We are experimenting with the change of pH buffer solution according to temperature with the provided temperature compensation cord.
But the value is not correct.
Why not? please answer about my question.
(3)Put the pH electrode into the standard solution whose pH value is 7.00，or directly shorted the input of the BNC connector.Open the serial monitor of the Arduino IDE,you can see the pH value printed on it,and the error does not exceed 0.3. Record the pH value printed,then compared with 7.00, and the difference should be changed into the "Offset" in the sample code. For example,the pH value printed is 6.88,so the difference is 0.12.You should change the "# define Offset 0.00" into "# define Offset 0.12" in your program.
Is there a problem if the measured value exceeds 0.3 and the offset value is adjusted too much?
We are experimenting with the change of pH buffer solution according to temperature with the provided temperature compensation cord.
But the value is not correct.
Why not? please answer about my question.
2018-07-12 20:31:56 Hi, my name umarjunaid i have your ph meter module and sample arduino code.i review it for understanding but i can't find how do you come up with volatge formula pHValue = 3.5*voltage+Offset;. and if we are using 3.3v microcontrol then this formula changes or not please tell me . 
anonymous
anonymous 2018-07-12 17:58:11 You can use a jumper wire connect the BNC connector, like the attachment (the red line), then see if the out put is 7.00, this is the way to test if the adaptor is good, if it is 7.00, then there should be some problem with the probe, if it is not, then probably the board is broken. 
robert.chen
robert.chen 2018-07-06 14:21:14 Yes, we tested it with a pH 7.0 buffer solution.
More specifically,
When the purchased pH sensor was first immersed in the 7.0 buffer solution, the pH value was about 7.9. I gave the offset value -0.9.
If you enter the offset value as -0.9 as above, is there a problem with the measured value?
During the experiment, When the offset value is less than 0.3, and The pH value is different when the offset value is over 0.3.
Ah! And the BNC connector is in use as it is purchased.
The pH sensor connection was connected to the Aduino as provided in the documentation.
'What is the BNC connector?' This means asking the length of the BNC connector? anonymous
More specifically,
When the purchased pH sensor was first immersed in the 7.0 buffer solution, the pH value was about 7.9. I gave the offset value -0.9.
If you enter the offset value as -0.9 as above, is there a problem with the measured value?
During the experiment, When the offset value is less than 0.3, and The pH value is different when the offset value is over 0.3.
Ah! And the BNC connector is in use as it is purchased.
The pH sensor connection was connected to the Aduino as provided in the documentation.
'What is the BNC connector?' This means asking the length of the BNC connector?
anonymous 2018-07-05 18:40:22 What is the value you read in pH=7.00 solution, what is you just short the BNC connector? Is the pH = 7.00? robert.chen
robert.chen 