Test Products International 556C1 - Manual (Page 7)

Area equation for Round Ducts:
AREA (A) = 3.14 X (Radius X Radius)
7. Press the SAMPLE AREA button, the earlier measured area will be
displayed. The left digit on the LCD will be flashing
8. If the calculated area is 1.00, press the numeric button 1 followed by the
decimal button followed by the numeric key for 0, 0, 0. Then press the
ENTER button.The enter button will only work when all four digits are
entered. “1.000” will be displayed on the lower part of the display after
the input has been completed.
9. Position the probe at the desired location for measurement.
10. Read the flow on the display, it will take several minutes
until the readings get stable after the probe is positioned.
11. Press the ESC/HOLD button to freeze the display after taking a
measurement is finished. “DH” will be displayed on the LCD.
12. Press the ESC/HOLD button again to return to normal operation.
13. If you want to record the reading changes, press the RECORD button
when the reading gets stable. The “REC” symbol will be displayed. The
meter will record the minimum, maximum and average readings.
Air Flow Measurement Continued
6. Measure the area to be measured and calculate the square
footage or square meters.
Area equation for Rectangular Ducts:
AREA (A) = Height (H) X Width (W)
6 7
Radius
Height (H)
Width (W)
Common Rectangular Duct Sizes with Area
DUCT SIZE AREA
(Inches) (sq.ft)
8” X 10” 0.444
8” X 10” 0.556
8” X 12” 0.667
8” X 14” 0.778
8” X 15” 0.833
8” X16” 0.889
8” X18” 1.000
8” X 20” 1.111
Common Round Duct Sizes with Area
DUCT SIZE AREA
(Inches) (sq.ft)
4” 0.087
5” 0.136
6” 0.196
7” 0.267