UEi Test Instruments DAFM4 - Manual (Page 10)

9
DIAGRAM OF LOCATIONS
ROUND DUCT ACCESS HOLE LOCATION
For round ducts drill three holes at 60 degrees separation. This will
allow you to cover all locations recommended using the log-Tchebycheff
method for round ductwork.
Locate all access holes in a straight section of ductwork.
24”
24”
1.8”
6.9”
12”
17.1”
22.2”
DAFM4
CFM
VOL
LW
MODE HOLD START STOP
EXIT [HOLD TO EXIT AVG MODE]
LW-D-AREA
ON / OFF (SET)
MAX / MIN AVG
Access Hole Location
Access
Holes
D
(<10”)
60º
60º
Log-Tchebycheff Rule for Round ducts