Chauvin Arnoux C.A 822 Manual De Funcionamiento página 10

1.2 Commands
4
3
1. Backlighting/Unit Changing Button
2. HOLD Button (freezes the screen)
3. 3-Way Switch : ON/OFF and selection of thermometric
measurement units
4. Button allowing selection from among the various available
functions : MAX, MIN, MAX-MIN difference, average over
two seconds.
2. OPERATION
The air must flow across the probe, from the back (screw
side) towards the front. The arrows indicate the direction of
air flow.
For increased accuracy, maintain the propeller axis at an
angle of 20° with respect to wind direction.
For reliable measurements, avoid areas where obstacles
are likely to cause turbulence.
2.1. Procedure :
1. Turn on the instrument, selecting the desired temperature
measurement units.
2. Outside, determine the approximate wind direction, using
when possible a flag, wind vane, air duct, etc.
3. Place the probe in the correct direction of air flow.
4. Wait a few seconds for the measurements to stabilize.
5. If necessary, freeze the display (HOLD).
NB : It is possible to make flow measurements. Multiply air
velocity by the cross-sectional area of the air duct (the flow
values calculated are approximate, due to the uncertainty of
the value of the cross-sectional area and the possible presence
of a screen, deflector, etc.).
2
1
10