Honeywell UDA2182 manual Performing Calibration Trim Introduction

Input Calibration

8.7.5Performing Calibration Trim Introduction

For most applications entering the cal factor for each cell will achieve satisfactory system performance. However, it is possible to perform a calibration trim procedure in which the Analyzer and cell combination are used to measure a reference solution of known conductivity; the reading of the Analyzer is adjusted to match.

The same procedure can be used to adjust the Analyzer’s reading while the cell is in the process, if a reference instrument is used to determine the process conductivity. In this case, the process fluid becomes the “reference solution”.

Calibration trim is recommended for acid concentration measurements above 5%.

Materials

To perform calibration trim using a standard reference solution, follow the instructions in Table 8-9.

Materials required are:

•A reference solution of known conductivity near the point of interest, with the temperature controlled (or measured and compensated) to within ± 1 °C. Conductivities of potassium chloride solutions are provided in Table 8-8. Solutions must be prepared with high-purity de-ionized, CO2-free water, and dried potassium chloride.

•For acid concentration applications, a certified reagent grade solution with the temperature controlled.

•A container for the reference solution, large enough to immerse the cell to measuring depth.

•De-ionized water to rinse the cell.

January 2009 UDA2182 Universal Dual Analyzer Product Manual 159