Enter the concentration of impurities at upstream point (ppm) and the concentration of impurities at downstream point (ppm) into the Purge Factor Calculator. The calculator will evaluate the Purge Factor. 

Purge Factor Formula

The following two example problems outline the steps and information needed to calculate the Purge Factor.

PURF = IU / ID

Variables:

  • PURF is the Purge Factor ( )
  • IU is the concentration of impurities at upstream point (ppm) 
  • ID is the concentration of impurities at downstream point (ppm) 

How to Calculate Purge Factor?

The following steps outline how to calculate the Purge Factor.


  1. First, determine the concentration of impurities at upstream point (ppm). 
  2. Next, determine the concentration of impurities at downstream point (ppm). 
  3. Next, gather the formula from above = PURF = IU / ID.
  4. Finally, calculate the Purge Factor.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

concentration of impurities at upstream point (ppm) = 50

concentration of impurities at downstream point (ppm) = 2

PURF = IU / ID = ?