Extech Instruments AN500 User manual

USER GUIDE
Hot Wire CFM/CMM Thermo-Anemometer
Model AN500
ft/min
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F

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Introduction
Thank you for selecting the Extech Hot Wire CFM/CMM Thermo-Anemometer. This instrument
measures air flow and temperature by placing the sensor into an airway such as a duct or a vent. The
sensor is situated at the end of the telescoping wand for convenience. This device is shipped fully
tested and calibrated and, with proper use, will provide years of reliable service. Please visit our
website (www.extech.com) to check for the latest version of this User Guide. The Extech Instruments
brand, a wholly owned subsidiary of FLIR Systems, Inc., is ISO-9001 certified.
Description
Meter Description
1. Probe input jack (insert probe plug here)
2. AC adaptor jack
3. Power ON-OFF button
4. Left arrow button
5. SET button
6. UNIT button
7. MAX-MIN button
8. STORE-RECALL button
9. ZERO and Backlight button
10. Down arrow button
11. Right arrow button
12. Up arrow button
13. LCD display
Note: Battery compartment and Tilt Stand located on the back of the meter
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ft/min
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Push-button Description
Power: Switches the meter ON and OFF
C/F: Select the temperature units
MAX/MIN: Press to Record and track the highest (MAX) and lowest (MIN) reading
STORE: Store readings into memory
RECALL: Display STORED readings
UNIT: Air velocity units or airflow units of measure
ZERO: Press to zero the display
BACKLIGHT: Turn LCD backlight ON and OFF
SET: Atmospheric compensation setting or airflow
parameters setting
◄►▲◄: Atmospheric compensation adjustment
arrows (also used for general menu navigation)
Probe Description
1. Probe Connector
2. Probe cabling
3. Telescoping sensor handle - Extends to 39” (1m)
4. Sensor opening (Air must flow through this
opening in the direction of the arrow shown in item
5 below for proper measurement)
5. Air direction arrow image
6. Ergonomic handle grip
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Operation
Initialization and Zero
The meter should always be zeroed at temperature before use using the ZERO button. Do not
rely on the initial zero display.
Notes:
The meter does not display negative numbers.
Open antenna to desired length.
1. Connect the sensor to the input jack on top of the meter and open antenna to desired length.
2. Switch the meter ON using the Power button. The meter will perform a self-test during which the
display will show SELF CHECK.
3. Select the desired temperature units by holding in the C/F select button. The LCD will reflect the
selection.
4. Select the desired air velocity units using the UNIT button. The LCD will reflect the selection.
5. Place the sensor in the area to be measured and allow a short time for the sensor to reach the
temperature of the air under test.
6. Press the ZERO button to zero the meter.
Taking Air Velocity Measurements
1. Zero the meter as described above.
2. Place the sensor in the air current to be measured. Have the air flow in the direction of the arrow
shown on the top of the sensor head.
3. View the air velocity and temperature readings on the LCD Display. The top LCD display
indicates the Air Velocity reading. The lower LCD display indicates the temperature reading.
MAX/MIN Function
1. To begin capturing the Minimum (MIN), Maximum (MAX), and Average (AVG) readings, press
the MAX-MIN button momentarily. The RECORD icon will appear on the LCD (flashing on and
off).
2. Take readings as described previously.
3. Press MAX/MIN button again to stop recording.
4. The MAX-MIN-AVG display screens will automatically scroll from one to the next showing the
highest (MAX), lowest (MIN), and average (AVG) readings captured since the MAX-MIN button
was first pressed.
5. Press the MAX-MIN button again to continue recording. The RECORD icon will continue
flashing.
6. Press and hold the MAX-MIN button for 1 second to exit the MAX-MIN mode and return to the
normal operating screen. The MAX-MIN-AVG readings will be reset.

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Auto Power OFF
The meter is equipped with an Auto Power OFF (APO) feature. The meter will automatically switch
OFF after 10 minutes of inactivity (no button pressed). Press and hold the POWER button for 1
second to disable the APO feature (the APO display icon will switch OFF). When the meter is
powered ON for the next session, the Auto Power OFF feature will be engaged again.
Change Units of Measure
1. Press the CF/UNIT button momentarily to switch between units of measure (m/s, km/hr, MPH,
ft/min, knots, CMM and CFM).
2. Press and hold CF/UNIT button for 1 second to switch between C and F temperature units.
Store Readings (Datalogging)
1. Press the RECALL/STORE button momentarily to store and hold the reading.
2. Press the RECALL/STORE button again to return to normal measurement mode.
Recall Readings
1. Press and hold the RECALL/STORE button for 1 second to enter recall mode.
2. Momentarily press the ►or ◄button to scroll through the memory locations and view the stored
data.
3. Press the RECALL/STORE button once more to exit recall mode. The meter will display 'END'
and return to normal operation.
Up to 36 readings can be stored in the AN500
Clear Stored Readings
While in RECALL mode press and hold RECALL/STORE button for 1 second to clear stored data.
The meter will display 'CLEAR MEM' then return to normal operation.
Atmospheric Pressure Compensation Setting
1. Press and hold the SET button for 1 second to enter Atmospheric Pressure Compensation
Adjustment mode.
2. Momentarily press the ▲or ▼button to adjust the PA from 500-1010 mbar.
3. Press the SET button to enter the next step.
4. Momentarily press the ▲or ▼button to adjust the GAIN from 0.00-2.00.
5. Press and hold the SET button for 1 second to store the settings in non-volatile memory and
return to the normal measurement mode. Or press the SET to return normal operation. The
atmospheric pressure compensation parameters will reset to the previous setting when next on.
6. While in atmospheric pressure setting, the unit will return to normal operation if no button is
pressed for 8 seconds. The data will not be stored.

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Zero Adjustment
Press and hold the ZERO button for 1 second to zero the reading.
Backlight
Press the Zero/BL button at any time to turn on/off the backlight.
Airflow Parameters Settings
1. While in airflow measurement mode press and hold SET for 1 second to enter next step.
2. Momentarily press the ►or ◄button to choose circle or rectangle function.
3. Press SET to enter next step.
4. Press ▲or ▼to adjust R in circle mode or L and W in rectangle mode. Adjustment will be from
0.0-101.5 cm in CMM mode or 0.0-40.0 in CFM mode.
5. Press SET to enter next step.
6. Press ▲or ▼to adjust GAIN from 0.10-1.00.
7. Press and hold the SET button for 1 second to store the settings in non-volatile memory and
return to the normal measurement mode. Or press the SET to return normal operation. The
airflow parameters will reset to the previous setting when next on.
8. While in Airflow parameters setting, the unit will return to normal operation if no button is
pressed for 8 seconds. The data will not be stored.

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Battery Replacement
When the displayed battery symbol appears empty or begins to blink, replace the batteries as
soon as practical. If battery voltage is too low the meter will not switch ON. The battery compartment
is located on the rear of the instrument (behind the tilt stand) secured by one Phillips head screw.
1. Open the rear battery compartment by first swiveling out the tilt stand.
2. Remove the Phillips head screw.
3. List the compartment cover to access the batteries.
4. Replace the six ‘AA’ 1.5V batteries observing polarity.
5. Replace the battery compartment cover and secure with the Phillips head screw.
EU users are legally bound by the Battery Ordinance to return used batteries to community
collection points or wherever batteries / accumulators are sold.
Disposal in household trash or refuse is prohibited.
Disposal: Follow the valid legal stipulations with respect to the disposal of the device at the
end of its lifecycle
Battery Safety Reminders
Please dispose of batteries responsibly; always observe local, state, and federal regulations
with regard to battery disposal.
Never dispose of batteries in a fire. Batteries may explode or leak.
Never mix battery types. Always install new batteries of the same type.

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Specifications
General Specifications
Circuit configuration Custom one-chip LSI microprocessor circuit
Display Dot Matrix LCD backlit display
Measurements m/s (meters per second), km/h (kilometers per hour), ft/min (feet/per
minute), knots (nautical miles per hour), MPH (miles per hour), CMM
(m3/min), and CFM (ft3/min), Temperature: °C, °F
Temperature sensor Two temperature sensors on glass pad
Min/Max Recording Capture Maximum (MAX), Minimum (MIN), and Average (AVG) readings
Datalogger 36 readings can be stored and recalled
Operating Temperature 0 to 50 °C (32 to 122°F)
Operating Humidity Max. 80% RH
Power Supply Six (6) 1.5V ‘AA’ batteries
Power Consumption Approx. 30 mADC
Weight 355g (0.78 lbs.) including batteries & probe
Dimensions Main instrument: 180 x 72 x 32 mm (7.1 x 2.8 x 1.3”)
Sensor: 12mm (0.5”) diameter
Telescoping handle with cable: 2.1m (7’) max. length with cable
Range Specifications
Units Range Resolution Accuracy
0.0 to 9.99 m/s 0.01 m/s
m/s 10.0 to 20.0 0.1 m/s ±(3.0%rdg+0.2m/s)
km/h 0.0 to 75.0 km/h 0.1 km/h ±(3.0%rdg+0.7km/h)
ft/min 0 to 4000 ft/min 1 ft/min ±(3.0%rdg+38ft/min)
MPH 0.0 to 45.0 MPH 0.1 MPH ±(3.0%rdg+0.4MPH)
knots 0.0 to 40.0 knots 0.1 knots ±(3.0%rdg+0.4knots)
Units Range Resolution Gain
CMM (cubic
meters per minute) 0 to 1298.0 m3/min 0.1 m3/min 0.10-1.00
CFM (cubic feet
per minute) 45922 ft3/min 1 ft3/min 0.10-1.00
mbar 502-1012 mbar 2 mbar 0.00-2.00
Power Consumption’=(1+(1010/mbar-1)*gain)*power consumption
CMM=(60*m/sec*R*R*PI*gain)/40000 Circle
CMM=(60*m/sec*L*W*gain)/10000 Rectangle
CFM=(ft/min*R*R*PI*gain)/576 Circle
CFM=(ft/min*L*W*gain)/144 Rectangle
R & L & W: 1.5-101.5cm (0.5) or 0.6-40.0in. (0.2)
Temperature 0 to 60oC (0 to 140 oF) 0.1 oF and oC 1.0
oC (1.8 oF)
Note: m/s: meters per second; km/h: kilometers per hour; ft/min: feet per minute; Knots: nautical miles per hour;
MPH: miles per hour; CMM: cubic meters per min; CFM: cubic ft per min

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Useful Equations and Conversions
Area equations
The volume of air flowing through a duct or vent can be determined by taking the area of the duct
in square units (i.e. square feet) and multiplying this value by the measured linear velocity (i.e., feet
per minute). This gives: ft/min x ft2= ft3/min (CFM)
Cubic equations
CFM (ft3/min) = Air Velocity (ft/min) x Area (ft2)
CMM (m3/min) = Air Velocity (m/sec) x Area (m2) x 60
Units Conversion Table
m/s ft/min knots km/hr MPH
1 m/s 1196.85 1.944 3.6 2.237
1 ft/min 0.00508 10.00987 0.01829 0.01136
1 knot 0.5144 101.27 11.852 1.151
1 km/hr 0.2778 54.68 0.54 10.6214
1 MPH 0.447 88 0.869 1.6093 1
Copyright ©2013 FLIR Systems, Inc.
All rights reserved including the right of reproduction in whole or in part in any form
www.extech.com
A = pi x R
2
R
A = W x H
W
H