TSI Instruments AccuBalance 8370, Operation And Service Manual

Page: 52 / 58

44 Appendix B
Figure 15 . Pressure Drop through the A
CCU
B
ALANCE
If you wish to make back pressure corrections, you must first
determine the back pressure correction factor, Cb. The back pressure
correction factor, Cb, can be determined as follows:
Vo
Cb = ---- (8-1)
V
where V and Vo are the average air velocities in the duct ahead of the
diffuser with and without the capture hood in place, respectively. With
the known correction factor, the back-pressure corrected flow can be
determined using Equation (8-2):
Back-pressure corrected flow = Displayed flow x Cb (8-2)
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