User Manual
User Manual Model 45158 Mini Hygro Thermo-Anemometer
Introduction
Congratulations on your purchase of Extech’s Model 45158
Anemometer. The dual display indicates Air Velocity and Humidity, Dew
Point, Ambient Temperature, or Temperature with wind-chill factor. With
careful use, this meter will provide years of reliable service.
Operation
Turning the meter ON and OFF
Press the ON/OFF/HOLD button to turn the meter ON
Press and hold the ON/OFF/HOLD buttons for approx. 3 seconds to turn it OFF
The meter’s Auto Power OFF feature turns the meter OFF after 20 minutes of inactivity
Change the lower display parameter
With the meter ON, press and hold down the ON/OFF/HOLD button
While continuing to hold the ON/OFF/HOLD button, press the UNITS/MODE button
repeatedly to step through Temperature (oF/oC), Humidity (RH%), Dew Point (TD), &
Temperature with wind-chill factor (WCI). Note that the center display is Air Velocity.
Change the Air Velocity unit of measure
Turn the meter OFF. Press and hold down both buttons until the display turns on and
begins blinking then release both buttons
Press the UNITS/MODE button repeatedly to step through the units (see specs for list)
After 5 seconds the meter switches back to normal operation mode automatically
Select temperature units (oC or oF)
Turn the meter OFF first. Press and hold down both buttons until the display turns on
and begins blinking then release the buttons
Press both buttons momentarily to change temperature units
After 5 seconds the meter switches back to normal operation mode automatically
Taking Measurements
Position the meter so that the airflow enters the meter vane from the rear of the meter
(opposite side of front panel logo). A tripod mount is located on the bottom of the meter.
Max Hold
Max Hold represents the highest measurement taken since the meter was turned on
Press the UNITS/MODE button to display the Max reading (MAX icon appears)
Press the UNITS/MODE button repeatedly to step through to the normal operating
mode
Average mode
5 or 10 reading averages can be displayed in the Average Mode.
Press UNITS/MODE 3 times for 5 reading averaging or 4 times for 10 readings
To exit this mode, press the UNITS/MODE button until the icons on the left disappear
Data Hold
Data Hold freezes the most recent displayed reading
Press and hold the ON/OFF/HOLD button to activate Data Hold
As long as the ON/OFF/HOLD button is held the reading will remain on the LCD
Copyright © 2013 FLIR Systems, Inc.
All rights reserved including the right of reproduction in whole or in part in any form
www.extech.com
45158-EN V3.4 8/13
Meter Description
1 Vane impeller
2 Impeller set screw (on rear of meter)
3 Relative Humidity sensor
4 Temperature sensor
5 LCD display
6 ON/OFF, HOLD key
7 UNITS, MODE key
8 Battery compartment (on rear)
9 Tripod mounting hole
10 Lanyard (neckstrap)
Specifications
Measurement
Range
Resolution
Accuracy (% of reading)
MPH (Miles per hour)
1.1 to 62.5 MPH
0.2 MPH
± (3% + 0.4 mph)
km/hr (kilometers per
hour)
1.8 to 100.6 km/h
0.7 km/h
± (3% + 1.4 km/hr)
Knots (nautical miles
per hour)
1.0 to 54.3 knots
0.3 knots
± (3% + 0.6 knots)
m/sec (meters per
second)
0.5 to 28.0 m/s
0.1 m/s
± (3% + 0.2 m/s)
ft/min (feet per
minute)
100 to 5500 ft/min
20ft/min
± (3% + 40 ft/min)
Beaufort force
1 to 17 BF
1 BF
± 1
Temperature
0 to 122
o
F (-18 to 50
o
C)
0.1
o
F/C
± 1.8
o
F (± 1
o
C)
Relative Humidity
10 to 95%
1%
± 5% RH
Dew Point
32 to 122
o
F (0 to 50
o
C)
0.1
o
F/C
± 3.6
o
F (2
o
C)
General Specifications
Display
Dual LCD with low battery and multifunction indicators
Sensors
Sapphire bearing, non-corrosive vane for air velocity;
Precision thermistor for temperature measurements
Average Mode
Choice of 5 or 10 reading averaging (2 second factory
default)
Max and Data Hold
Displays
Max recalls the highest reading; Data Hold freezes the
display
Sample time
1 reading per second for air velocity and temperature
(1 reading per 15 seconds for humidity with 2 second
updates)
Water-resistant
To 3’(1m)
Operating conditions
5 to 122
o
F (-15 to 50
o
C) / < 80% RH
Power supply
Lithium battery (CR-2032 or equivalent) / 400 hour battery
life
Dimensions / Weight
Instrument: 133 x 70 x 19mm( 5.25 x 2.75 x 0.75”)
Vane: 1’(24mm) diameter /3 oz.(95 g)
Maintenance
Battery Replacement
The 45158 has a low battery indicator (battery symbol). Important: Turn the meter off
before opening the battery compartment. Using a coin, turn the battery compartment
cover CLOCKWISE to remove it. Once opened, observe the position of the battery,
placing the new one in the same position. Secure the battery compartment cover and
dispose of the lithium battery in accordance with local, state, or national disposal codes.
All EU users are legally bound by the Battery Ordinance to return all 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 in respect of the disposal of the
device at the end of its lifecycle
Other Battery Safety Reminders
Never dispose of batteries in a fire. Batteries may explode or leak.
Never mix battery types. Always install new batteries of the same type.
Impeller Replacement
Remove the set screw next to the impeller assembly (on the rear of the meter).
Twist the impeller assembly counter-clockwise to the OPEN position and remove
it.
Install impeller by inserting & twisting the new impeller assembly clockwise
Tighten the set screw.
CFM Measurements
Measure the area of the duct using the diagrams below for rectangular and circular
ducts (If the duct measurements are made in inches, divide the inches by 144 to get the
area in square feet). Plug the area value (in square feet) in the cubic equations below.
Note that the air velocity must be plugged into the cubic equations also.
CFM (ft
3
/min) = Air Velocity (ft/min) x Area (ft
2
)
CMM (m
3
/min) = Air Velocity (m/sec) x Area (m
2
) x 60
Warranty
FLIR Systems, Inc. warrants this Extech Instruments brand device to be free of defects in parts and
workmanship for one year 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 for authorization. Visit the website www.extech.com for
contact information. A Return Authorization (RA) number must be issued before any product is returned. 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. FLIR
Systems, Inc. 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. FLIR’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.
Calibration, Repair, and Customer Care Services
FLIR Systems, Inc. offers repair and calibration services for the Extech Instruments products we sell.
NIST certification for most products is also provided. Call the Customer Service Department for information
on calibration services available for this product. Annual calibrations should be performed to verify meter
performance and accuracy. Technical support and general customer service is also provided, refer to the
contact information provided below.
Support Lines: U.S. (877) 439-8324; International: +1 (603) 324-7800
Technical Support: Option 3; E-mail: support@extech.com
Repair & Returns: Option 4; E-mail: repair@extech.com
Product specifications are subject to change without notice
Please visit our website for the most up-to-date information
www.extech.com
FLIR Commercial Systems, Inc., 9 Townsend West, Nashua, NH 03063 USA
ISO 9001 Certified