CTRFLV spread function is a method for approximating the CT Tables for 4 log inactivation of Viruses. The CT Tables (from EPA Disinfection Profiling and Benchmarking Guidance Manual) are used to find the CT Required for certain conditions (temperature, pH, and log inactivation). This function will return the value from the table for 4 log inactivation given a disinfectant, water temperature and pH.
For more information on CT Calculations, click here: Calculating CT in WIMS
CTRFLV(Disinfectant ID, Water Temperature, pH)
Disinfectant ID is a constant based on the type of disinfectant used for inactivation. Disinfectant ID has one of the following settings:
- Free Chlorine
- Chlorine Dioxide
Water Temperature is the water temperature in Degrees C
pH is the measured pH of the water
This function can be used instead of the CT function which uses the CT Tables directly. This function (used in Illinois) interpolates between values in the tables whereas the CT function uses only values in the table.
V84 = CTRFLV(1, C3, C4) = 10.67 where cell C3 = 2 (Deg C) and C4 = 7.5 (SU).
Variable 84 will contain the CT Value for 4 Log Inactivation of Viruses by free chlorine.