We have conductivity cell with constant of 0.100 cm-1. I know, that 0.01 M KCl is often used for the calibration, however it is said, this control standard can only be used for measuring cells with cell constant in the range 0.450 - 0.500 cm-1 or 0.800 - 1.200 cm-1. In general, which control standard solution can be used to calibrate the cell constant of 0.100 cm-1? Thank you.
The actual problem is to calibrate the conductivity meter. If the cell constant is reported with 3 sig fig ( 0.100 cm-1 ) you don't need more. You may use a conductivity standard with a lower specific conductivity (50...150 microS/cm), e.g.,:
https://www.fishersci.com/shop/products/conductivity-standard-84-s-cm-sachets-10x20-ml/01914041
but the verification is very difficult to do:
http://www.thermofisher.co.nz/Uploads/file/Environmental-Industrial/Environmental-Monitoring-Safety/Water-Monitoring-Treatment/Tech-Tip-Top-Ten-Conductivity-Mistakes-NZ.pdf
Read also
https://sensorex.com/blog/2017/11/29/conductivity-cell-constants/
Thank you for answer. So basically, when using cell constant of 0.100, there is no control standard for determination of exact cell constant value, just standards with a lower specific conductivity to verify the value. Also, we use 5 microS/cm, the measured conductivity is higher than the value stated on the bottle, but as I read, these standards can have tolerance up to 0.5 microS/cm.
As above, but be careful to carry out calibrations at exactly the same temperature, electrolytes, particularly those employed as calibration solutions, have high enough temperature coefficients to introduce errors in the calibration procedure due to much increased ion mobility.
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