Horiba Scientific 6561S-10C, Instruction Manual

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63
Reference
If the ion concentration (activity) is set to the logarithmic axis, a linear
relationship like in the graph below is created between the electrode potential
measured with the ion selective electrode and the ion concentration (activity).
Fig. 6 Relationship between monovalent cation concentration (activity) and electrode potential
To perform the above quantitative analysis using an ion selective
electrode, either (1) use an ion meter or meter with an ion
measurement function that has a logarithmic arithmetic function or
(2) create a calibration curve using semi-logarithmic graph paper.
10 0 10 2
Ion concentration (activity)
∆ 2.303 RT/nF
Potential gradient
59.16 mV/decade (at 25ºC)
Electrode potential (mV)
Tip Tip