Operation - Extech Instruments AN300 User Manual

Operation
Air Velocity, Volume, and Temperature Measurements
1. Switch the meter ON by pressing the POWER
button again to switch the meter OFF.
2. Note that the meter will automatically enter the sleep mode after 20 minutes of inactivity.
To disable this feature: with the meter OFF, press and hold the POWER and the U/mode
buttons for 2 seconds. The LCD will display 'n' as the meter switches ON. Now the sleep
mode is disabled and the user must press the POWER button momentarily to switch the
meter OFF.
3. When the meter is ON, the air velocity reading is displayed on the upper display digits in
meters per second (m/s) or feet per minute (fpm). The lower display area can show Air
Volume (CMM/CFM) or Air Temperature (°C/°F) readings, use the L/mode button to toggle
between the two. Note that an area measurement must be programmed into the meter (in
the SETUP mode) before accurate volume measurements can be made.
4. Place the meter's vane in the air stream. The air must enter the vane from the rear of the
meter. The temperature sensor is located at the center of the vane on the rear of the meter.
5. Read the measurement data on the LCD.
6. To change between Imperial and Metric units of measure refer to the SETUP mode section.
7. To measure the Air Volume of a duct, first measure the duct's area (see the Appendix for
area calculations) and then enter the area value in the meter's SETUP mode in in
After the area value has been entered, press the L/mode button to switch the lower display
from Air Temperature to Air Volume. Place the meter in the air stream to measure volume.
8. Optionally, measure Air Volume with an airflow cone adaptor by first attaching one of the
adaptors to the meter (the optional cone adaptor kit includes a round and a square cone; kit
part number AN300‐C). The meter will automatically recognize the adaptor and the 'INSERT
Cone Shape' prompt will appear on the LCD (the adaptor icon will also appear). Select round
or square using the meter's keypad. Note that, regardless of the AREA setting in the SETUP
mode, the meter will default to the dimensions of the attachment (Square: 356 x 346mm
[13.6 x 13.6"); Round: 210mm [8.3"] diameter). NOTE: Ensure that the airflow adaptor is well
mounted and locked before taking measurements.
LCD backlight
Press the U/mode button to switch ON the LCD backlight. The backlight will automatically switch
OFF after approximately 10 seconds to conserve battery power. Note that the backlighting
switches ON automatically when the meter is switched ON by the user.
button momentarily. Press the POWER
6
2 2
or cm .
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