Extech Instruments 407119 User manual

User's Guide
Heavy Duty Hot Wire CFM Thermo-Anemometer
Model 407119

Model 407119Version 1.5 Oct 28, 2004
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Warranty
EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in parts and
workmanship for three years from date of shipment (a six month limited warranty applies on sensors and
cables). If it should become necessary to return the instrument for service during or beyond the warranty
period, contact the Customer Service Department at [phone] ext. 210 for authorization or visit our
website at www.extech.com (click on ‘Contact Extech’ and go to ‘Service Department’ to request an RA
number). A Return Authorization (RA) number must be issued before any product is returned to Extech. The
sender is responsible for shipping charges, freight, insurance and proper packaging to prevent damage in
transit. This warranty does not apply to defects resulting from action of the user such as misuse, improper
wiring, operation outside of specification, improper maintenance or repair, or unauthorized modification.
Extech specifically disclaims any implied warranties or merchantability or fitness for a specific purpose and
will not be liable for any direct, indirect, incidental or consequential damages. Extech's total liability is limited
to repair or replacement of the product. The warranty set forth above is inclusive and no other warranty,
whether written or oral, is expressed or implied.
Introduction
Congratulations on your purchase of the Extech 407119 Thermo-Anemometer. The
407119 utilizes a telescoping antenna with built-in air velocity and temperature
measurement transducers. CFM (cubic feet per minute) measurements are displayed
after manually entering the area of the duct and then taking an air velocity measurement.
The 407119 includes a MIN/MAX display and a 20-point averaging feature. Careful use
of this meter will provide years of reliable service.
Specifications
General Specifications
Display Dual function 4-digit LCD
Measurement units Air Velocity: m/s, km/h, ft/min, knots, mph;
Air Flow: CMM (m3/min) and CFM (ft3/min);Temp: °C and °F
Data hold Freezes displayed reading
Sampling rate 1 second approx.
Sensors Air velocity sensor: Glass bead thermistor
Temperature sensor: Thermistor
MAX/MIN Memory Record and view Maximum and Minimum readings
Automatic Power off Auto shut off after 15 minutes
Data Output RS-232 PC serial interface with 16-bit data stream output
Operating
Temperature
Meter: 32 to 122°F (0 to 50°C)
Operating Humidity Max. 80% Relative Humidity
Power Supply Six (6) ‘AAA’ 1.5V batteries
Power Current Approx. DC 30mA
Weight (meter only) 0.78 lbs. (355g)
Dimensions Main instrument: 7.1 x 2.8 x1.3" (180 x 72 x 33mm)
Telescoping Sensor: 0.5" (12.7mm) diameter head;
37" (.94m) maximum antenna length with 78" (2m) cable

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Range Specifications
Air Velocity Range Resolution Accuracy
0.20 – 9.99 m/s 0.01m/s (meters per second)
10.0 to 20.0 m/s 0.1
km/h (kilometers per
hour)
0.7 – 72.0 km/h 0.1
ft/min (feet per minute) 40 – 3940 ft/min 1
mph (miles per hour) 0.5 – 44.7 mph 0.1
knots (nautical miles per
hour)
0.4 to 38.8 knots 0.1
±5% full scale
Air Flow Measurements Range Resolution Area
CMM (cubic meters per
minute)
0 - 999,900 m3/min 0.001 to 100 0 to 9,999m2
CFM (cubic feet per
minute)
0 - 999,900 ft3/min 0.001 to 100 0 to 9,999ft2
Air Temperature Range Resolution Accuracy
32 to 122oF
(0 to 50oC) 0.1oF/C ±1.5oF (0.8oC)
Meter Description
1. Sensor input
2. RS-232 PC interface jack
3. LCD Display
4. Keypad
5. Rubber protective holster
6. Battery compartment (rear)
7. Air Velocity Sensor
8. Sliding sensor cover
9. Telescoping antenna
Note: To access the rear battery compartment
first remove the meter's rubber protective holster.
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Operation
Initialization and Zero
The meter should always be zeroed at temperature before use. Do not rely on a zero display.
The meter does not display negative numbers.
1. Connect the sensor to the input jack on top of the meter.
2. Turn on the meter using the Power button. The meter will perform a self-test during
which the display will count down from 9999 to 0000.
3. Select the VELOCITY function using the FLOW/VELOCITY button. The LCD will
display VEL when the velocity mode is selected.
4. Select the desired temperature units using the C/F select button. The LCD will reflect
the selection.
5. Select the desired air velocity units using the UNIT button. The LCD will reflect the
selection.
6. Place the sensor cover in the UP (ZERO) position.
7. Place the sensor in the area to be measured and allow a short time for it to reach
temperature.
8. Press the ENTER/RESET button to zero the meter.
Air Velocity Measurements
1. Open the antenna to the desired length.
2. Slide the air velocity sensor cover down.
3. Place the sensor in the air current to be measured. Have the air flow meet the sensor
head in the direction of the white dot on the sensor head.
4. View the air velocity and temperature readings on the LCD Display. The large main
LCD display shows the Air Velocity reading. The lower LCD sub-display shows the
temperature reading.

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Air Flow Measurements (CMM / CFM)
NOTE: Temperature is not displayed in the FLOW mode.
1. Perform the Initialization and Zero described earlier.
2. Select the FLOW mode using the FLOW/VELOCITY button. The LCD will display
FLOW when the flow function has been selected.
3. Select the desired air flow units: CMM (cubic meters per minute) or CFM (cubic feet
per minute) using the UNIT button. The LCD will reflect the selection.
4. Calculate the area of the duct or vent in square feet (not inches) or meters.
5. Press the AREA button to begin entering the area in m2or ft2. The left digit will begin
flashing.
Use the ►button to select the digit to set.
Use the ▲button increase the value of the flashing digit
Use the ▼button to decrease the value of the flashing digit
Use the ●RECORD/RECALL button to set the decimal point.
Press the ENTER/RESET button to save the area.
When the area has been entered, the bottom display will indicate the area entered in ft2
or m2.
6. Insert the probe into the area to be measured and the display will display the airflow.
The main LCD displays the air flow in CFM or CMM.
Flow Modes
For air flow measurements, three modes apply: Press the FLOW MODE button to select
one of the modes
NORMAL MODE, default mode, where the actual flow is indicated.
2/3V MAX MODE: LCD displays 2/3 the measured value.
AVG MODE: Up to 20 readings can be taken separately and averaged. Select the AVG
mode via the FLOW MODE button and then press the AVG START button to take a
reading. Up to 20 readings can be taken and averaged. The lower LCD display
provides a 1 to 20 counter that increments each time a reading is taken. The main LCD
displays the averaged air flow.
Data Hold Feature
1. While taking measurements, press the HOLD button to freeze a reading.
2. The HOLD indicator will appear on the LCD when the display is in Data Hold mode.
3. Press HOLD again to return to normal operation.
Maximum and Minimum Recording
The RECORD/RECALL feature allows the user to record and view the highest (MAX) and
lowest (MIN) readings.
1. Press the RECORD/RECALL button once. The REC indicator will appear on the
display and the meter will begin keeping track of the MAX and MIN values.
2. To view the MAX reading, press RECORD/RECALL again. The MAX indicator along
with the maximum reading will appear on the LCD display.
3. Press RECORD/RECALL again to view the minimum value, the MIN indicator along
with the minimum reading will appear on the LCD display.
4. To return to normal operation, press and hold the RECORD/RECALL button for
approx. 3 seconds. The display indicators REC, MAX, and MIN will disappear.
Note: Auto Power Off is disabled in the RECORD mode.

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
Support Hotline [phone]
Tech support: Ext. 200; Email: [e-mail]
Repair/Returns: Ext. 210; Email: [email protected]
Website: www.extech.com
Auto Power Off
To save battery life, the meter will automatically shut off after approximately 15 minutes of
operation. To disable this feature, press the RECORD/RECALL button and enter the
RECORD mode.
PC Interface
The 407119 is equipped with a 3.5mm jack (meter top) for connection to a PC for data
acquisition purposes. To obtain PC interface cabling and WindowsTM data acquisition
software, contact Extech Instruments. Instructions for use are provided with the optional
data acquisition kits.
Battery Replacement
When the LBT icon appears on the LCD, the 9V battery must be replaced.
1. Remove the rubber holster that surrounds the entire meter
2. Slide off the rear battery compartment
3. Replace the 9V battery
4. Affix the battery compartment cover and the meter holster
Calibration and Repair Services
Extech offers repair and calibration services for the products we sell. Extech also provides
NIST certification for most products. Call the Customer Service Department for information
on calibration services available for this product. Extech recommends that annual
calibrations be performed to verify meter performance and accuracy.
Copyright ©2004 Extech Instruments Corporation
All rights reserved including the right of reproduction in whole or in part in any form.

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Useful Equations and Conversions
Area equation for rectangular or square ducts
Area equation for circular ducts
Cubic equations
NOTE: Measurements made in inches
must be converted to feet or meters before using the above formulae.
Unit of Measure Conversion Table
m/s ft/min knots km/h MPH
1 m/s 1196.87 1.944 3.6 2.24
1 ft/min 0.00508 10.00987 0.01829 0.01138
1 knot 0.5144 101.27 11.8519 1.1523
1 km/h 0.2778 54.69 0.54 10.6222
1 MPH 0.4464 87.89 0.8679 1.6071 1
Width (W)
Height (H)
Area (A) = Width (W) x Height (H)
CFM (ft3/min) = Air Velocity (ft/min) x Area (ft2)
CMM (m3/min) = Air Velocity (m/sec) x Area (m2) x 60
Radius Area (A) = 6x r2
Where 6 = 3.14 and r2= radius x
radius