Measuring Air Speed And Temperatures - General DAF3009 User Manual

When the icon of the mode you want appears, flashing, on the top
line, press the MODE button once to stop it from flashing. Doing
this will cause one or more measurement unit icons below to
begin flashing. Press the MODE button again to stop those icons
from flashing. This causes the meter to enter real-time
measurement mode for the chosen parameter (air/wind speed,
airflow volume, RH or enthalpy).
To hold any pair of measurements ("freeze" the readouts),
press the HOLD button. To release the hold and resume displaying
real-time values, press the button again. This function is very
useful for making measurements in low light or when the source
of air or wind is above your head, below your knees, or around a
corner. You can make a measurement, hold it, and then read the
display up to 5 minutes later after positioning the LCD at eye level.
Why do you have only 5 minutes? To extend battery life, the
DAF3009 automatically powers itself off following any 5-minute
period in which no front-panel button is pressed.

MEASURING AIR SPEED AND TEMPERATURES

To make an air speed measurement, unsnap the vane and
sensor protection cap (Fig. 1, Callout A) and let it hang from the
unit by the wrist strap. Turn the vane at the top of the unit
perpendicular to the source of air or wind. It makes no difference
whether the front of back of the vane faces the flow. The
measured air speed value will appear on the upper readout.
Allow a few seconds for the reading to stabilize.
The DAF3009's factory default air speed measurement unit is
feet/minute (ft/m). To change the air speed unit, begin by
pressing the UNIT button. This will cause ft/m to begin flashing
on the right side of the upper readout. Then, within 15 seconds
(before the backlight extinguishes), press the SET button. This will
change the flashing ft/m term to mph, also flashing. Press the
SET button again and mph will turn to knots. Press it again to
change knots to m/s.
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