Extech Instruments 407112 User manual

User's Guide
Heavy Duty Vane Thermo-Anemometer
Model 407112

Model 407112 Version 4.1 03/062
Warranty
EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in
parts and workmanship for one year 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 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 407112 Vane Anemometer. The 407112
measures air velocity in five units of measure: feet per minute (ft/min), meters per
second (m/sec), miles per hour (MPH), kilometers per hour (km/hr), & nautical miles per
hour (knots). The remote vane freely rotates in response to air flow. An internal
thermistor allows the 407112 to measures air temperature in centigrade or Fahrenheit
units. Careful use of this meter will provide years of reliable service.

Model 407112 Version 4.1 03/063
Specifications
Circuit description Custom LSI microprocessor design
Display Dual function 9999 count LCD display
Measurement units m/s, km/h, ft/min, knots , mph, Temperature oC/oF
Data hold Freezes reading on the display
Sensor Structure Air velocity sensor: Conventional twisted vane arm with low-
friction ball-bearing
Temperature sensor: Precision thermistor
Memory Recall Record and Recall Maximum (MAX) and Minimum (MIN)
readings
Auto Power off After 15 minutes
Data Output RS 232 PC serial interface for use with model 407001 data
acquisition PC interface kit
Operating Temperature 32 °F to 122 °F (0 °C to 50 °C)
Operating Humidity Max. 80% RH
Power Supply 9V battery
Power Consumption Approx. 8.3mA DC
Weight 0.84 lbs. (381g)
Dimensions Main instrument: 7.1 x 2.8 x1.3” (180 x 72 x 32mm)
Sensor Head: 2.8” (72 mm) diameter
Air Velocity Range Specifications
Measurement Range Resolution Accuracy
(of reading)
ft/min (feet per minute) 80 – 4930 ft/min 1 ft/min ± (2% + 40 ft/min)
m/s (meters per second) 0.4 - 25.0 m/s 0.01 m/s<10m/s ± (2% + 0.2 m/sec)
km/h (kilometers per hour) 1.4 - 90.0 km/h 0.1 km/h ± (2% + 0.8 km/hr)
mph (miles per hour) 0.9 - 55.9 mph 0.1 mph ± (2% + 0.4 mph)
knots (nautical miles per hour) 0.8 to 48.6 knots 0.1 knots ± (2% + 0.4 knots)
Temperature Range Specifications
Range (probe only) Resolution Accuracy
32oF to 122oF (0oC to 50oC) 0.1oF (0.1oC) ± 1.5oF (0.8oC)

Model 407112 Version 4.1 03/064
Meter Description
1. Protective rubber holster (must be removed to open the meter case or to access the
battery compartment)
2. LCD display for air velocity/temperature measurements and various status indicators
3. Push-buttons:
•POWER – Press to turn the meter ON or OFF
•HOLD – Press to freeze the displayed reading
•oC/oF – Select unit of measure for temperature measurement displays
•MAX/MIN - Press to record/recall highest (MAX) and lowest (MIN) readings
•UNIT – Press to select the unit of measure for air velocity
4. Battery compartment on lower back of meter (remove protective holster to access)
5. Sensor input jack
6. PC Interface jack
7. Vane sensor

Model 407112 Version 4.1 03/065
Operation
Connecting the sensor
1. The sensor plug is inserted in the meter’s sensor jack at the top of the meter. The plug
and jack are keyed so that the plug can only fit in the jack one way.
2. Turn the plug carefully until it lines up with the jack and then firmly push the plug in
place. Do not apply undue force or try to twist the plug side-to-side.
3. If the sensor is not connected to the meter or if the sensor is defective, the LCD display
will indicate dashed lines in place of an air velocity reading.
Meter Power
1. Press the POWER button to turn the meter on. If the display does not switch on, check
that a fresh 9V battery is installed. To access the rear battery compartment, first
remove the meter’s rubber protective holster.
2. Press the POWER button to turn the meter off.
3. The meter is equipped with an AUTO POWER OFF feature. The meter automatically
shuts off after 10 minutes to conserve battery energy. To defeat this feature, press the
MAX/MIN button. This will activate the Record / Recall feature.
Measuring Air Velocity and Temperature
1. Determine if the vane sensor will be held or placed on a tripod; a threaded tripod
mounting hole is located on the vane sensor handle.
2. Place the sensor in the air stream under test. Ensure
that the air enters the vane on the opposite side of the
yellow dot. Refer to the diagram.
3. Read the Air Velocity and Temperature measurements
directly on the LCD.
4. To calculate Air Volume in CFM (cubic feet per minute)
or CMM (cubic meters per minute) refer to the ‘Useful
Equations and Conversions’ section.
Selecting the Temperature unit of measure (oC/oF)
Press the oC/oF key to select the temperature unit of measure. The display will indicate the
currently selected unit of measure.
Selecting the Air Velocity unit of measure
Press the UNIT button to change the unit of measure for Air Velocity measurements. The
display will reflect the current selection. A list of measurement units is printed on the meter
faceplate beneath the UNIT button and in the specifications earlier in this manual.
Data Hold
To freeze the LCD display, momentarily press the HOLD button. The 'DH' icon will appear
on the LCD and the reading will remain unchanged. Momentarily press the HOLD button
again to return to normal operation (the 'DH' icon will switch off).
Record and Recall MIN / MAX Function
1. To begin capturing the Minimum (MIN) and Maximum (MAX) air velocity and
temperature readings, press the MIN/MAX key.
2. Now, use the MIN/MAX button to toggle the view from MIN to MAX and from MAX to
MIN readings. The ‘MAX’ or ‘MIN’ will appear along with the recalled reading for
convenience.
3. To return to normal operation, press and hold the MIN/MAX button until the ‘MAX’, and
‘MIN’ icons switch off.
airflow
yellow
dot
Side view of Vane

Model 407112 Version 4.1 03/066
RS-232 PC Interface
The 407112 includes an RS-232 PC interface serial data port. This port is located on the
top of the meter next to the sensor input jack. The interface port is a 3.5mm phone jack
(mono). This port is intended for use with Extech’s Data Acquisition Software/Hardware kit
which includes a cable for connection between PC and meter. The interface permits the
capture, storage and display of measurements on a PC. Refer to the software User’s
Manual for detailed instructions.
Maintenance
Battery Replacement
The 407112 is powered by one 9V battery. When the ‘LBT’ low battery icon appears on the
LCD or if the display does not switch on when the POWER button is pressed, replace or
install a 9V battery.
1. Remove the protective rubber jacket surrounding the meter
2. Open the rear battery compartment using a coin or a wide blade flat-head screwdriver
3. Replace the battery and carefully pack the connected battery into the compartment
4. Close the compartment and replace the holster
Cleaning and Storage
Wipe the meter and vane with a damp cloth as needed. Do not apply abrasive, solvents, or
other cleaners to the surface of the meter or vane. Store with the battery removed and
avoid extreme temperature and humidity.

Model 407112 Version 4.1 03/067
Useful Equations and Conversions
Volume Measurements
To determine CFM (cubic feet per minute) or CMM (cubic meters per minute) in a duct, the
area of the duct must first be measured (use the equations below). Then multiply an air
velocity measurement by the area measurement to obtain CFM or CMM.
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) = x r2
Where  = 3.14 and r2= radius x radius

Model 407112 Version 4.1 03/068

Support Hotline [phone]
Tech support: Ext. 200; Email: [email protected]
Repair/Returns: Ext. 210; Email: [email protected]
Website: www.extech.com
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.