Extech Instruments 407119A User manual

POWER
HOLD
ESC
REC.
Enter
UNIT / ZERO FUNCTION
SETUP
AREA
AVERAGE
Ft/min73.2 F
407119A
Hot Wire
Anemometer
CFM
User's Guide
Heavy Duty Hot Wire CFM Thermo-Anemometer
Model 407119A

Model 407119A Version 5.0 October 20052
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 to 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
www.extech.com for contact information. 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 407119A Thermo-Anemometer. The
407119A measures air velocity, air volume, and air temperature. It uses a telescoping
probe antenna to allow convenient access to grills and diffusers. Careful use of this
meter will provide years of reliable service. The Model 407119A features are listed
below.
Features
•Combination hot wire probe (for air velocity) and thermistor sensor (for temperature)
deliver rapid and precise measurements even at low air velocity values.
•Slim probe design with telescoping antenna for easy grill and diffuser access
•Air Velocity, Air Volume, and Air Temperature measurements
•20 Reading Average feature
•Zero adjustment
•Data Hold and Record/Recall Max/Min features
•Auto Power OFF
•PC Interface (RS-232) with optional software and cable for data acquisition
Applications
Environmental testing, air conveyors, flow hoods, clean rooms, air balancing,
fans/motors/blowers, furnace velocity, paint spray booths, and others.

Model 407119A Version 5.0 October 20053
Specifications
General Specifications
Display Dual function 5-digit LCD
Measurement units Air Velocity: m/s, km/h, ft/min, knots, mph;
Air Flow: CMM (m3/min) and CFM (ft3/min);Temperature: °C and °F
Data hold Freezes displayed reading
Sampling rate Display update rate:1 second (approx.)
Sensors Air velocity and temperature sensors: Thermistor type
MAX/MIN Memory Record and view Maximum and Minimum readings
Average feature Averages up to 20 readings
Automatic Power off Auto shut off after 15 minutes
Data Output RS-232 PC serial interface with 16-bit data stream output
Operating Temp. 32 to 122°F (0 to 50°C)
Operating Humidity Max. 80% Relative Humidity
Power Supply Four (4) ‘AA’ 1.5V batteries or optional AC adaptor
Power Current 70mA DC (approx.)
Weight (meter only) 1.15 lbs. (521g) with batteries installed
Dimensions Main instrument: 7.9 x 3.0 x 1.5" (200.0 x 76.2 x 36.8mm)
Telescoping Sensor: 0.5" (12.7mm) diameter head
Min length of sensor: 8” (260mm); Max. length: 37” (0.94m) with 5.5’
(1.7m) cable
Range Specifications
Air Velocity Range Resolution Accuracy (of rdg)
m/s (meters per second) 0.2 – 17.0 m/s 0.1 ±(5% + 5 digits)
km/h (kilometers per hour) 0.7 – 61.2 km/h 0.1 ±(5% + 20 digits)
ft/min (feet per minute) 40 – 3346 ft/min 1 ±(5% + 100 digits)
mph (miles per hour) 0.5 – 38.0 mph 0.1 ±(5% + 10 digits)
knots (nautical miles per hour) 0.4 to 33.0 knots 0.1 ±(5% + 10 digits)
Air Flow Measurements Range Resolution Area Range
CMM (cubic meters per min.) 0 – 36,000 m3/min 0.001 to 1 0.001 to 30.0 m2
CFM (cubic feet per minute) 0 – 1,271,200 ft3/min 0.01 to 100 0.01 to 322.91ft2
Range Resolution AccuracyAir Temperature
32 to 122oF
(0 to 50oC) 0.1oF/C ±1.5oF (0.8oC)

Model 407119A Version 5.0 October 20054
Meter Description
1. Display
2. POWER button
3. HOLD and ESC button
4. REC and ENTER button
5. UNIT, ZERO, and ▲up arrow button
6. Function and ▼down arrow button
7. AVG. START, CLEAR, and ►right arrow button
8. AREA SET button
9. Tilt stand
10. Battery compartment / Cover
11. Tripod mount
12. LCD contrast adjustment pot
13. System reset switch
14. RS-232 Output terminal
15. DC9V power adaptor
11
9
10
1
2
3
5
7
4
6
8
15 14 13 12

Model 407119A Version 5.0 October 20055
Operation
Initialization and Zero procedures (please follow these steps before use)
Important Note: The meter’s probe locking switch must
be in the locked position (with the probe inserted) for
the meter to turn on and operate correctly. Refer to the
accompanying diagram or the diagram at the top of the
meter for switch orientation.
For the best accuracy and for proper operation, the
following steps must be performed.
1. Connect the sensor to the input jack on top of the
meter by first unlocking the sensor jack and then
inserting the sensor plug. Lock the sensor jack after
the probe is inserted.
2. Press the POWER button to turn on the meter. The meter will perform a self-test during
which the display will count down from 9999 to 0000.
3. Select the air velocity function using the FUNCTION button. The LCD will display the
most recently selected unit of measure for air velocity.
4. To change the temperature units of measure (C/F), use the advanced programming
mode discussed later in this manual.
5. Momentary presses of the UNIT button changes the air velocity units. The LCD will
reflect the selection.
6. Place the sensor cover in the up (ZERO) position (see diagram below).
7. Open the telescoping sensing antenna to a convenient length.
8. Place the sensor in the area to be measured and allow a short time for it to stabilize to
the ambient temperature.
9. To Zero the meter display, press and hold the ZERO button until the second beep.
Warning! Do not touch the air velocity or temperature thermistors inside the sensor head
while moving the sensor cover.
TOP VIEW OF METER
LOCKED Position
UNLOCKED Position

Model 407119A Version 5.0 October 20056
Air Velocity Measurements
1. Follow the Initialization and Zeroing procedures above before continuing.
2. Open the antenna to the desired length.
3. Slide the air velocity sensor cover down.
4. Press the POWER button to turn the meter on.
5. 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
(as shown in diagram).
6. 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 (left) and the unit of measure (right).
7. To turn the meter off, press and hold the POWER button until the meter switches off.
Air Flow (Volume) Measurements (CMM / CFM)
NOTE: Temperature is not displayed while the meter is in the Air Flow mode.
1. Follow the steps in the Initialization and Zeroing section before continuing.
2. Select the air flow mode using the Function button. The LCD will display CMM (cubic
meters per minute) or CFM (cubic feet per minute) when Air Flow is selected.
3. Press the UNIT button momentarily to select the desired air flow units: CMM or CFM.
The LCD display will reflect the selection.
4. Calculate the area of the duct or vent under test (refer to the Useful Conversions and
Equations section in the back of this manual for assistance). Be sure to compute the
area of the vent or duct in square feet or meters. If you have the area in inches, convert
inches to feet before programming the meter with the area value.
5. Press the AREA SET button to begin entering the area in m2or ft2. The left digit will
begin flashing. Follow the steps below to enter the area of the duct or vent in question:
Use the ►button to select a digit to change (digit will flash)
Use the ▲button increase the value of the flashing digit
Use the ▼button to decrease the value of the flashing digit
6. Press the REC/Enter button and then the AREA SET button to save the new area
value
7. After the area has been entered, the new area value will be shown on the lower left of
the LCD display in ft2or m2. If the unit of measure is CFM, the area will be shown in
square feet. If the unit of measure is CMM, the area will be shown in meters squared.
8. Press the ESC button to abort the programming at any time.
9. Place the probe in the area under test. The main LCD digits will indicate the air flow in
CFM or CMM. If the CFM or CMM reading exceeds 99999, use the displayed X10
multiplier to calculate the reading.
10. To turn the meter off, press and hold the POWER button until the meter switches off.

Model 407119A Version 5.0 October 20057
AVERAGE Feature for the Air Flow Mode
In the Average mode, up to 20 readings can be stored and averaged.
1. In the Air Flow Mode (discussed earlier), press the FUNCTION button momentarily
until the AVG icon and a ‘zero’ appears on the lower LCD display line.
2. Press the AVG START button to record the current reading. A ‘1’ will appear on the
lower LCD line indicating that one reading has been stored.
3. Press the AVG START for up to a total of 20 measurements. The number on the lower
LCD line will increment with each press of the AVG START button letting the user
know how many readings are currently being averaged. Note that only the averaged
reading is shown while in this mode, not the actual reading.
4. To clear (erase) all of the currently stored readings and start again, press and hold the
AVG button until the meter beeps twice. Note that the counter resets to ‘0’ and that the
meter is ready to start another averaging session.
5. Use the FUNCTION button to exit this mode of operation.
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 (MAX) and Minimum (MIN) Recording
The MAX / MIN Record-Recall feature allows the user to record and view the highest and
lowest readings during a measurement session.
1. Press the REC 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 REC again. The MAX indicator along with the
maximum reading will appear on the LCD display.
3. Press REC 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 REC button for approx. 3 seconds
(until the meter beeps). The display indicators REC, MAX, and MIN will disappear.
Note: Auto Power Off is disabled in the RECORD mode.
Auto Power Off
To save battery life, the meter will automatically shut off after approximately 15 minutes of
operation. To temporarily disable this feature (until the meter’s power is cycled), press the
REC button and enter the RECORD mode. Alternatively, go to the advanced programming
section (later in this manual) for instructions on how to disable it long term.

Model 407119A Version 5.0 October 20058
Advance Programming Mode
From the Air Velocity mode of operation, press and hold the SET button until the meter
beeps and a ‘1’ is displayed. The advanced programming mode is now accessed. The
Auto Power OFF Enable/Disable and the Temperature Units selections are available in the
advanced programming mode. Use the ESC button to exit this mode at any time.
Auto Power Enable/Disable
The first parameter in the advanced mode is the Auto Power OFF enable/disable. Use the
up and down arrow keys to select the desired value. ‘0’ defeats the Auto Power OFF
feature; ‘1’ enables the Auto Power OFF feature. Momentarily press the SET button to
move to the next parameter temperature units (see below).
Temperature Units selection (C/F)
The second parameter in the advanced mode is the Temperature Units selection. Use the
up and down arrow keys to select the desired value. ‘0’ selects degrees ‘C’; ‘1’ selects
degrees ‘F’. Press the ESC button to exit the advanced programming mode.
System Reset
If the meter’s display ‘locks up’ and/or the button presses do not cause the display to
change, try a system reset. To reset the meter, use one of the following methods.
1. Move the probe lock switch from the ON to the OFF to the ON position again. Turn the
meter on.
2. While powering the meter, press the RESET switch (side compartment) using the point
of a paper clip.

Model 407119A Version 5.0 October 20059
PC Interface
The 407119A is equipped with a 3.5mm jack (side compartment) for connection to a PC for
data acquisition purposes. The meter’s data output is a 16 bit data stream. To obtain PC
interface cabling and WindowsTM data acquisition software, contact Extech Instruments.
Instructions for use are provided with the software. The PC interface cable schematic, data
stream protocol, and RS-232 communication settings are provided below.
PC Interface Cable schematic
Protocol for 16-bit data stream
D0 End Word = ‘0D’
D1 & D8 Displayed reading; D1 = LSD; D8 = MSD. For example,
For a displayed reading of 1234, D8 through D1 is 00001234
D9 Decimal point (right to left):
0 = no decimal; 1 = 1 place; 2 = 2 places; 3 = 3 places
D10 Polarity: 0 = positive; 1 = negative
D11 & D12 Displayed unit of measure: 01 = oC; 02 = oF; 08 = m/s; 09 = knots;
10 = km/hr; 11 = ft/min; 12 = MPH; 84 = CMM; 85 = CFM;
0A = Square meter (area); 0B = Square feet (area)
D13 1 = Upper LCD display digits; 2 = Lower LCD display digits
D14 Always ‘4’
D15 Start word ‘02’
RS-232 Settings
Baud rate: 9600
Parity: No parity
Data bits: 8
Stop bits: 1
Meter
3.5mm jack
Center pin.............................Pin 4
Ground / Shield.....................Pin 2
PC
DB-9 pin
Pin 5
2.2K
Resistor
W

Model 407119A Version 5.0 October 200510
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Support line [phone]
Technical support: Extension 200; E-mail: [e-mail]
Repair & Returns: Extension 210; E-mail: [email protected]
Product specifications subject to change without notice
For the latest version of this User’s Guide, Software updates,and other
up-to-the-minute product information, visit our website: www.extech.com
Extech Instruments Corporation,285 Bear Hill Rd., Waltham, MA 02451
Battery Replacement
When the battery icon appears on the lower left corner of the LCD display, the four (4) ‘AA’
batteries must be replaced.
1. Remove the rear Phillips head screw
2. Slide off the rear battery compartment
3. Replace the batteries
4. Secure the battery compartment
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 ©2005 Extech Instruments Corporation
All rights reserved including the right of reproduction in whole or in part in any form.