The sample measurement for the low buffer capacity/low conductivity liquid such as pure water, cleaning solution for semiconductors, boiler water, tap water, groundwater, river water and precipitation is extremely difficult to perform. The pH indication because unstable or there is no reproducibility in the measurement..
(1) Calibrate the glass electrode in the standard solution, and rinse it with pure water.
(2) Fill the measuring container with the sample, and immerse the electrode for more than 10 minutes.(3) Rinse the measuring container and the electrode with new sample (different solution mentioned in (2) above).
(4) Do not wipe the container and electrode of the cleaning liquid out with filter papers or tissue papers. Keep the container and electrode getting wet, fill the sample slowly into the container without bubbling, and measure the sample pH value.
There are following electrodes for low conductivity water/non-aqueous solvents.
#9630-10D: Quick and stable measurement is possible for low conductivity samples or those with low buffering ability, such as tap water. Suitable for water quality testing at water treatment plants.
#6377-10D: This integrated electrode has good response to aqueous solutions in the low conductivity/low buffer capacity, and to non-aqueous solvents such as alcohol.