The meter is now ready to measure air flow (CFM). To clear the memory of the current multi-point
average readings, press and hold the
AVERAGE
key until the unit beeps twice, then release. The
unit must be in velocity/FPM mode in order to clear current average readings.
L. OBTAINING AIR FLOW (CFM) AVERAGE FOR MULTI-POINTS
Complete steps 1-4 in section D
Once all multi-point averages are determined:
1. Press
MODE
key once to confirm that the correct free area setting is locked into the instru-
ment (if the free area needs adjustment, make the necessary changes now)
2. Once the free area setting is correct, press
MODE
key again to enter air flow mode
3. Unit will now display average air flow reading and number of points measured.
The meter’s free area dimension has been set to 1.111 square feet which is the most commonly
used free area dimension in the USA. If you want to measure the air flow for a single point without
changing the area dimension:
1. Power the unit on and position the fan
2. Press the
MODE
key twice. You will then be in the air flow (CFM) mode The air flow displayed is
equal to the current air velocity reading (FPM x Free Area=CFM) times the 1.111 square feet.
We would suggest to set the free area dimensions before you start measuring the air velocity so
after you measure the air velocity you can jump to the air flow mode to view the cubic feet per
minute without further changing of the free area dimensions.
TROUBLESHOOTING
LOW BATTERY: indicates battery is low. Please replace with a new 9-volt battery.
NOTE
On initial startup the unit will display flow, area. ft/mph, knots, mil/h, cfm, km/h and cms.
4
SPECIFICATIONS:
Air Flow Range
Resolution
Accuracy
80 - 5900 ft/min
1
±3% FS
0.4 - 35 m/sec
0.01
±3% FS
Temperature
Resolution
Accuracy
+14 ˚F to 122 ˚F
0.1
±2.0 ˚F
-10 ˚C to 50 ˚C
0.1
±1.0 ˚C
Battery Life:
100 Hours
Display type:
LCD
Display Size:
1-1/4” x 1-5/8” (37 x 42 mm)
Maximum Reading:
9999
Dimensions
(L x W x D)
:
7-1/4” x 3” x 1-3/4” (133 x 76 x 45 mm)
Fan Diameter:
2-7/8” (70 mm)
RS232 Output Format:
TXXX. XF, VXXXXFTM/TXXX.XC, VXXXXMPS
Auto Power Off:
20 minutes
Data Hold
DCFM8906_Manual 7/3/03 2:43 PM Page 4
