English User's Manual

LCD display
Battery compartment (on rear)
Tripod mounting hole
Lanyard (neckstrap)
 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
45158-EU-EN V3.4 8/13
All rights reserved including the right of reproduction in whole or in part in
any form
ISO-9001 Certified
Copyright © 2013 FLIR Systems, Inc.
 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
 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
0.5 to 28.0 m/s
100 to 5500 ft/min
1 to 17 BF
-18 to 50oC (0 to 122oF)
10 to 95%
0 to 50oC (32 to 122 oF)
m/sec (meters per
ft/min (feet per
Beaufort force
Relative Humidity
Dew Point
To 1m(3’)
Lithium battery (CR-2032 or equivalent) / 400 hour battery
Instrument: 133 x 70 x 19mm( 5.25 x 2.75 x 0.75”)
Vane: 24mm (1”) diameter /95 g (3 oz)
Power supply
Dimensions / Weight
1 reading per second for air velocity and temperature
(1 reading per 15 seconds for humidity with 2 second
Sample time
-15 to 50oC (5 to 122oF) / < 80% RH
Max recalls the highest reading; Data Hold freezes the
Max and Data Hold
Operating conditions
Choice of 5 or 10 reading averaging (2 second factory
Average Mode
Sapphire bearing, non-corrosive vane for air velocity;
Precision thermistor for temperature measurements
± 3.6oF (2oC)
± 5% RH
± 1.8oF (± 1oC)
± (3% + 40 ft/min)
± (3% + 0.2 m/s)
± (3% + 0.6 knots)
± (3% + 1.4 km/hr)
Dual LCD with low battery and multifunction indicators
1 BF
Accuracy (% of reading)
± (3% + 0.4 mph)
General Specifications
0.3 knots
1.0 to 54.3 knots
Knots (nautical miles
per hour)
0.1 m/s
0.7 km/h
km/hr (kilometers per 1.8 to 100.6 km/h
0.2 MPH
MPH (Miles per hour) 1.1 to 62.5 MPH
Temperature sensor
Turning the meter ON and OFF
 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
Average mode
Relative Humidity sensor
Impeller set screw (on rear of meter)
Vane impeller
Meter Description
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.
CMM (m /min) = Air Velocity (m/sec) x Area (m ) x 60
CFM (ft /min) = Air Velocity (ft/min) x Area (ft )
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 Measurements
Impeller Replacement
Other Battery Safety Reminders
Never dispose of batteries in a fire. Batteries may explode or
Never mix battery types. Always install new batteries of the
same type.
Disposal: Follow the valid legal stipulations in respect of
the disposal of the device at the end of its lifecycle
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.
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.
Mini Hygro Thermo-Anemometer
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.
User Manual Model 45158