CN0428 pH calibration

Hi Cholowanow,

There is some mention of calibration in the user guide:

https://wiki.analog.com/resources/eval/user-guides/circuits-from-the-lab/cn0428

but few specifics, we'll contact the engineers that support this circuit.

In the meantime - Do you have calibration buffer solutions at your disposal?

-Mark

Hi Mark,

Yes I ahve buffers for pH 8.0, pH 4.01

Cholowanow

Hi Cholowanow,

The calibration for CN0428 is not exposed in the command line interface, mainly so calibrations programmed into the part are stored in flash memory and available every time the system powers on.

Take a look at the 'm355WqConfig.h' file. There you will find calibration instructions. I put a red box around the 6 lines to write your pH calibration values on. I would recommend setting DEBUG to 1 and reprogramming the board before making the measurements so that it prints out the voltages. Then when you put the calibration values into the config file, you can also set DEBUG to 0 again before reprogramming to suppress the extra information printouts.

And just in case you aren't familiar with reprogramming the CN0428 sensor boards yet, there is a wiki page on the topic: wiki.analog.com/.../cn0428-cn0429-programming-with-custom-firmware

Thanks,
Scott

Many Thanks for this answer I checked it and it works great. Thank You