Honeywell UDA2182 manual Recommendations for Successful Measurement and Calibration

Input Calibration

8.4 Recommendations for Successful Measurement and Calibration

Selection and care of electrode system or cell essential

Successful measurements and calibration depend upon selection and care of the electrode system or cells. Always prepare electrodes or cells and their mountings in accordance with the instructions supplied with them, observing temperature, pressure and flow limitations. Note the following recommendations:

pH/ORP Calibration

•Rinse electrodes thoroughly between buffer solutions.

•Always use HOLD, or otherwise deactivate control or alarm circuits before removing electrodes from the process.

•Standardize with a buffer solution, which is at about the same temperature and pH as the sample solution.

•Inspect and, if necessary, clean and/or rejuvenate the electrode system periodically according to experience and conditions.

Conductivity Calibration

•For most accurate temperature measurement and compensation, insulate the outer body of the cell to minimize the effect of ambient conditions on process temperature measurement.

•Rinse the cells thoroughly with de-ionized water before immersing in a reference solution.

•Always deactivate control or alarm circuits before removing cells from the process.

•Do calibration trim with a reference solution, which is at about the same temperature and conductivity as the process solution.

•Inspect and, if necessary, clean the cells periodically according to experience and conditions.

ATTENTION

For successful measurement in pure water applications where plastic piping is used, you may have to provide an earth ground for the cell. Run a wire from the black electrode terminal of the cell to one of the earth ground screws.

January 2009 UDA2182 Universal Dual Analyzer Product Manual 139