In your example, 50% @ 5" H2O, you would:
1) Check the flow range (based on the rubber stoppers removed).
2) Multiply the flow range by 50%. This is the uncorrected flow at 5" H2O.
3) Multiply the uncorrected flow value by the "temperature correction factor" in the chart. This is the corrected flow value at 5" H2O.
4) To convert the flow to a different depression (i.e. from 5" H2O to 10" H2O):
* Multiple the flow value in step 3 by the square root of 10/5.
So, let's say you where testing an intake port using the 105 cfm flow range and you got a reading of 50% with a 10 degree difference on the thermometers. Your corrected flow at 10" H20 would be:
105 x 0.50 x 0.992 x (10/5)^0.5 = 73.65 cfm @ 10" H20
if you wanted to correct the value to 28" H2O:
105 x 0.50 x 0.992 x (28/5)^.5 = 123.24 cfm @ 28" H2O
Here is a link to a set of instructions in case you don't have them.
http://www.freewebs.com/jawa634/supe...ing%20ocr).pdf