Extech Instruments NON-DISPLAY PORTABLE, 451126 User Manual

User's Guide

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Vane Thermo-Anemometer Datalogger
Model 451126

99 Washington Street
Melrose, MA 02176

Phone [phone]
Toll Free 1-800-517-8431

Introduction

Congratulations on your purchase of Extech's Thermo-Anemometer Datalogger. This
Vane-type 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
datalogger can record up to 2000 readings and the RS-232 interface provides PC data
transfer capability.

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176

o

C or oF units. The meter can also display air flow in CFM or CMM. The built-in

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Specifications

General Specifications

Display Dual 4-digit (9999 count) Multi-function LCD
Data hold Locks latest reading on the LCD display
Sensor Structure Air velocity sensor: Conventional twisted vane arm with low friction

Memory Recall Records Max/Min readings with push-key RECALL
Data Output RS-232 PC serial interface
Operating conditions

(Meter)
Operating conditions

(Vane)
Storage temperature Temperature: -40°F to 140°F (-40°C to 60°C)
Power 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);

Accessories 9V battery and carrying case

Range Specifications

Measurement

Feet per Minute (ft/min) 60.0 to 8800 0.1 ± (3% + 20 ft/min)
Meters per Second (m/s) 0.30 to 45.00 0.01 ± (3% + 0.1 m/s)
Kilometers per Hour (km/hr) 1.00 to 140.0 0.01 ± (3% + 0.4 km/hr)
Miles per Hour (mile/hr) 0.70 to 100.0 0.01 ± (3% + 0.2 mile/hr)
Knots 0.60 - 88.0 0.01 ± (3% + 0.2 knots)

Units Range Converter Resolution Accuracy

o

C 0.0oC to 45.0oC 0.2oC ±1.0oC

o

F 32.0oF to 113.0oF 0.4oF ±1.8oF

Range Resolution Area
CFM (ft3/min) 0 to 999900 0.001 to 100 0.001 to 9999

CMM (m3/min) 0 to 999900 0.001 to 100 0.001 to 9999

(sapphire) ball bearing. Temperature sensor: K-type thermocouple
built into vane. 1/4" mounting nut provided

Temperature: 32°F to 122°F (0°C to 50°C); Humidity: <80% RH;
Pressure: 500mB to 2 Bar
Temperature: 32°F to 140°F (0°C to 60°C); Humidity: <80% RH;

Pressure: 500mB to 2 Bar

Vane: 2.6 x 5.22 x 1.15" (66 x 132 x 29.2mm)

Air Velocity

Calibrated Range

Display

Resolution

Temperature

Air Flow and Area

(CMM: 0 to 45.00 m/s; CFM: 0 to 8800 ft/min)

Model 451126 Version 1.6 February 2004

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Accuracy

Meter Description

1. LCD Display

2. Vane Sensor

3. ON/OFF Key

4. RS-232 Connector

5. Function/Numeric Keypad

LCD Display Icon Definitions

o

AVE Average reading mode

is selected

MIN Minimum reading mode

is selected

2/3V 2/3V Maximum mode is

selected

MAX Maximum reading

mode is selected

VEL Air Velocity

measurement

READ Recalling stored

measurements

REC Appears when

recording readings

RS-232 PC Interface is

activated

ft2 Square feet MPH Miles per hour
m2 Square meters Km/h Kilometers per hour

C Temperature is displayed in degrees

o

F Temperature is displayed in degrees

CFM Cubic feet per minute (ft3/min)

CMM Cubic meters per minute (m3/min)

x100 Multiply reading by one hundred

X10 Multiply reading by ten

m/s Meters per second

ft/min Feet per minute

centigrade

Fahrenheit

Model 451126 Version 1.6 February 2004

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Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176

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Operation

n

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

o

a 20

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 .

Side view
of Vane

Tripod mount

Figure 2

o

20

Air directio

o

20

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)

Model 451126 Version 1.6 February 2004

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2/3Vmax Air Flow

1. Power the meter by pressing .

2. Press to select Air Flow. FLOW will display.

3. Press to select the desired units (CFM, CMM).

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 numeric keys to enter a new area value in
square feet. Press when finished.

5. Press until the 2/3V MAX icon appears on the LCD.

6. Determine the direction of the air to be measured. Move the Vane around the
center of the area being measured to read the maximum air velocity. The meter will
use the maximum reading obtained to determine the 2/3MAX Air Flow.

Average Air Flow

1. Power the meter by pressing .

2. Press to select Air Flow. FLOW will display.

3. Press to select the desired units (CFM, CMM).

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 numeric keys to enter a new area value.
Press when finished.

5. Press until AVE appears on the LCD display.

6. Press to clear the upper LCD.

7. Select a measurement location. Once a point is selected and a flow measurement
is displayed, press to average the flow reading.

8. Select the next measurement location and press again to average the
reading with previous readings. The value in the upper LCD line will increment for
each reading taken to show how many readings were averaged. The max is 12

readings.

Data Hold

Press to freeze the reading. The display will hold and an 'H' will appear on the LCD.
Press again to return to normal operation.

MAX and MIN Measurements

1. Press to enter MAX mode. The meter will only display the highest reading.

2. Press again to enter the MIN. The meter will only display the lowest reading.

3. Press to exit the MAX or the MIN mode.

Model 451126 Version 1.6 February 2004

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Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176

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