User`s guide

Appendix E – Measuring pH with UMC800 Controller and Durafet II Cap Adapter
Math Calculation
266 UMC800 Control Builder User’s Guide Release E
1/01
Math Calculation
Once the inputs are measured and standardization performed, the accumulated values are used in the math
calculation to determine a pH value. The calculation to be entered is:
7 – (273.16 + T1) / (273.16 + T) * (7 – (Bz + (MV – MVz) / ((MVs – MNz) / (Bs – Bz))))
Where:
T = Temperature measurement
T1 = Temperature during standardization
MV = Measures MV value
MVz = Millivolt value during Zero standardization
MVs = Millivolt value during Slope standardization
Bz = Buffer for Zero Standardization
Bs = Buffer for Slope standardization
See function blocks in Figure 78 for the math calculation configuration.
Figure 78 Math calculation configuration