UEi Test Instruments DAFM3 - Manual (Page 10)

Advanced Measurement Mode (Volume)
The DAFM3 can calculate the air volume, and display the result after
taking a 30 second average. The DAFM3 only measures the velocity of
the airflow, so entering an area into the meter is critical. This is also
one of the most involved portions of the DAFM3 operation.
Note: If the Enter key is pressed when trying to advance to “D”
(Diameter) or “AREA” by accident, the only method to recover is to
power the meter off and then back on.
Selecting the method to enter area
Use the following guide to determine the proper method;
1. LW (Length and Width) – Use for open square duct
2. D (Diameter) – Use for open round duct
3. AREA (Free Area) – Use when measuring at a grill.
For best results obtain the Ak or effective area from the grill
manufacture. If this is not available, estimate based on the information
listed earlier in this guide.
To access the desired mode for entering area first enter volume mode
by pressing and holding the MODE button until it beeps. Next scroll
through the options by pressing the “LW-D-Area” button. Icons in the
lower left will indicate you what method of area is currently selected.
The steps are as follows;
1. Press and hold “MODE” to change
to the volume (CFM) mode. The below
screen should appear. (This is the first
screen for the LW dimensions) Note the
“L” in the lower left corner indicating
Length is expected.
2. Press “LW-D-Area” to advance to
the diameter dimension entrance screen.
The icon in the lower left will now be
a “D” to indicate this is now expecting
Diameter.
3. Press “LW-D-Area” to advance
to the area dimension entrance screen.
The icon in the lower left will now be
“AREA” to indicate this is now expecting
Free Area.
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