Extech Instruments 451126 User Manual Download Page 4

Model 451126 V2.0  6/08 

Operation 

 

NOTE:

 For all air velocity or flow measurements, the air should pass through the vane 

from back to front. The rear of the vane can be found by locating the mounting nut. The 
front of the vane has the engraving "ANEMOMETER". For more accurate results, maintain 
a 20

o

 axis of air direction with the rear of the vane (refer to Fig.2). 

 

Air Velocity 

1. 

Power the meter by pressing        . 

2. 

Select Air Velocity measurement 

function by pressing        . VEL will 

appear on the LCD. 

3. 

Press           to select the desired unit 
of measure (ft/min, mph, km/h, m/s or 
knots) 

4. 

Place the vane in the air flow with the 
air direction matching the direction of 
the arrows printed on the inner walls 
of the vane. If the unit does not have the printed arrows, have the tripod mount side 
of the vane facing the air flow (see Fig.2). 

5. 

Air velocity will be displayed on the bottom line of the LCD. 

Temperature 

1. 

When the meter is measuring Air Velocity, Temperature is simultaneously being 
measured by the vane's built-in type-K thermocouple. 

2. 

Press             to select °C or °F. Temperature is displayed on the upper line of the 
LCD. 

Air Flow 

1. 

Power the meter by pressing             . 

2. 

Press            to select airflow. FLOW will display. 

3. 

Press            to select the desired unit of measure. (CFM, CMM). 

4. 

To enter the area value, press           . The lower display line will blank waiting for 
the user to program new data. Use the numeric keys to enter a new area value 

in 

square feet

. (REMINDER: if measurement is taken in inches, divide by 144 to 

obtain square feet). Press            when finished.  

Airflow is based on the specific dimensions of the duct being measured. For the 
meter to correctly measure CFM the user must input the area of the duct. Failing to 
input the correct area dimensions will result in erroneous readings. 

NOTE

: If the AVE or the 2/3MAX display icons are displayed in the upper left hand 

corner of the LCD, press            until they extinguish. 

5. 

Place the vane in the air flow (Fig.2). 

6. 

Wait approximately 2 seconds for a stabilized Air Flow reading.  

7. 

The equation below is used to calculate Air Flow: 

AIR FLOW = (AIR VELOCITY) x (AREA) 

20

20

o

o

Side view

of Vane

Tripod mount

Air direction

Figure 2

 

Summary of Contents for 451126

Page 1: ...ype Anemometer can indicate Air Velocity in five units of measure Feet per minute Meters per second Miles per hour Kilometers per hour and Knots with Temperature displayed in o C or o F units The mete...

Page 2: ...Supply 9V battery Battery life 50 hours typical Power Consumption Approx 3 mA DC Weight 0 77 lbs 350g Dimensions Meter 3 46 x 6 61 x 1 03 88 x 168 x 26 2mm Vane 2 6 x 5 22 x 1 15 66 x 132 x 29 2mm Acc...

Page 3: ...is displayed in degrees Fahrenheit 2 3V 2 3V Maximum mode is selected CFM Cubic feet per minute ft 3 min MAX Maximum reading mode is selected CMM Cubic meters per minute m 3 min VEL Air Velocity measu...

Page 4: ...y being measured by the vane s built in type K thermocouple 2 Press to select C or F Temperature is displayed on the upper line of the LCD Air Flow 1 Power the meter by pressing 2 Press to select airf...

Page 5: ...4 The previously stored area value will be displayed on the upper LCD display line To enter a new area value press The lower display line will blank waiting for the user to program new data Use the nu...

Page 6: ...the LCD indicating that the datalogging mode is activated 5 The maximum number of readings that can be stored is 2000 6 To stop datalogging press again The datalogger will automatically stop recordin...

Page 7: ...4 x 768 pixels 451126 Anemometer Operating System Compatibility Windows TM 95 98 NT 2000 XP VISTA Hardware Connection The meter connects to a PC with the supplied DB 9 to DB 9 interface cable The mete...

Page 8: ...le go to Windows Device Manager Ports It is here the COM PORTS will be listed If using the meter with a Serial to USB Adaptor make sure you install the driver that is supplied with the 3 rd party adap...

Page 9: ...3 min Air Velocity m sec x Area m 2 x 60 Units Conversion Table m s ft min knots km hr mph 1 m s 1 196 87 1 944 3 6 2 24 1 ft min 0 00508 1 0 00987 0 01829 0 01138 1 knot 0 5144 101 27 1 1 8519 1 152...

Page 10: ...ore 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 resulti...

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