What is an extrapolated result? (e.g. Q4)

Why is an extrapolated result different in FanTestic than on a DM32?

Q4 is a Flow result that is extrapolated to 4 Pa. For extrapolation of what the result would be at 4 Pa, a best-fit line on a graph (with a known slope) is needed.

The slope value is different for different enclosures, since the slope is dependent on enclosure leakage. To generate a line on a graph, you will either need to:

  1. Measure multiple points of data to compute a slope ('n' value), or you
  2. Guess a slope ('n' value)

FanTestic performs #1, whereas your DM32 performs #2. 

In other words, FanTestic software records multiple measurements to create a graph with a more precise slope (for example, n=0.5583).

The DM32 gauge, however, will create a graph by setting a guessed slope (for example, n=0.6000).

Hence, extrapolation for the Q4 result will be different from FanTestic than from a DM32 gauge. The more accurate result would be from a multipoint test using FanTestic.