Hi,
I am using sensorex's BNC probed type pH sensor ,from which i can able to read mV values but i need to interpret mV values to pH values.
I tried to interpret using Nernst equation E = Eo - (RT/nF)lnQ but i couldn't achieve.
Any help/suggestions are highly appreciated. Thank you.
The signalled paper may help: D.J. Graham, B. Jaselskis, C.E. Moore, "Development of the glass electrode and the pH response", J. Chem. Educ., 90(3) 2013, 345−351; dx.doi.org/10.1021/ed300246x
http://pubs.acs.org/doi/abs/10.1021/ed300246x
Hi Upendra,
a classical way should be to calibrate the sensor in pH buffer solutions of known pH. Typically, the voltage has a linear dependency on pH. If you have for example 3 buffer solutions of known pH, than you can perform a linear regression analysis E = n+ m*pH. You can than use your measured E and the coefficients n and m to calculate the unkown pH of a sample.
For freshwater, typically NBS buffer solutions are used. In seawater it's better to take seawater buffers. Dicksons guide to best practices for ocean CO2 measurement explains this (Dickson, A. G., C. L. Sabine, and J. R. Christian. 2007. Guide to best practices for ocean CO2 measurements, PICES Special Publication 3.).
Good luck! - Jens
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