F. CHANGING THE SETTINGS FOR IMPERIAL OR METRIC
The default setting for the measuring unit of air velocity is feet/min and the unit of temperature is
˚F. You can change the measuring units to meter/sec and ˚C by following these steps:
1. Press
ON
and
AVERAGE
at the same time.
2. Release
ON
first then
AVERAGE.
The LCD will show “ft/min” (default) on the upper right
corner and “˚F” on the lower right corner in small print.
a) Press
HOLD
key to change the measuring units to metric system;
press
AVERAGE
key for imperial measuring units
b) Press the
MIN/MAX REC
key and an “S” will show on the LCD. Press
HOLD
to confirm
and save the changed value. At this time, the baud rate “2400” (default) appears on
the screen to be followed by section G, step 1 for changing RS-232 output (if neces-
sary)
G. SETTING THE RS-232 OUTPUT
(OPTIONAL ACCESSORY)
By following the steps under section E you will see a “2400” number on the screen. This is the
default setting of the baud rate for the RS232 output. You can change the setting to “1200” by fol-
lowing these steps:
1. After following steps 1 & 2 in section E press the
HOLD
key. The setting can be changed
back to “2400” by pressing the
AVERAGE
key
2. Please remember to save your changes by pressing the
MIN/MAX REC
key. An “S” is dis-
played on the screen. Press the
HOLD
key to confirm and save the changed value. The
meter will return to air velocity mode automatically
H. AUTO POWER OFF
The unit will turn off automatically after 20 minutes to save the battery. This will be preceded by 3
beeps. Press the ON key and the unit will resume operation.
I. MEASURING FEET/MIN, MPH, KNOTS, M/S, KM/H
1. IN IMPERIAL: Press the
SEL: MPH/H•KNOT
key and the reading will change from ft/min to
mil/h to knots in turn.
2. IN METRIC: Press the
SEL: MPH/H•KNOT
key and the reading will change from m/s to km/h
to knots in turn.
J. DIRECT MEASURING OF AIR FLOW (SINGLE POINT) CFM
Air velocity measurement is calculated by multiplying the air velocity readings by the free area
dimensions. Free area is usually published by the grill or register manufacturer you are servicing.
You must determine the free area of the air source before entering it into the meter.
1. Power unit on
2. Press
MODE
once (you will hear one beep). Meter will display “AREA” in upper case letter-
ing and “1.111” will appear.The first digit will be flashing.
3. Press the
HOLD
key to increase the number.
4. Press the
AVERAGE
key to advance to next number. Follow Step 3 and repeat.
5 Press the
MODE
key once all digits have been entered. The word “flow” will appear.
K. CALCULATING FREE AREA
If the free area is not published by the grille manufacturer use one of the following formulas to
determine the correct value:
1) For square or rectangular grills:
Length
x
Width ÷ 144
2) For round grills:
Radius
2
x
π
(3.1415)
÷ 144
3
DCFM8906_Manual 7/3/03 2:43 PM Page 3
