Extech Instruments 407123 User Manual

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User's Guide

Hot Wire Thermo-Anemometer Model 407123

Introduction

Congratulations on your purchase of the Extech Hot Wire Anemometer. This meter measures air flow and temperature by placing the sensor into an airway such as a duct or a vent. The sensor is situated at the end of the telescoping wand for convenience and has a protective cover that slides up and down. The meter includes an RS-232 PC Interface jack for use with the Model 407001 Data Acquisition software and interface cable kit. Careful use of this meter will provide years of reliable service.

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Model 407123 V5.2 2/2006

Specifications

General Specifications

Circuit configuration

Custom one-chip LSI microprocessor circuit

Display 3-1/2 digit (2000 count) dual LCD display Measurements m/s (meters per second), km/h (kilometers per hour), ft/min

(feet/per minute), knots (nautical miles per hour),

MPH (miles per

hour), Temperature: °C, °F

Data hold Freezes reading on display Sensor Structure Air velocity sensor: Glass bead thermistor

Temperature sensor: Precision thermistor Min/Max Recording Record and Recall Maximum (MAX) and Minimum (MIN) readings PC Interface RS 232 PC serial interface jack for use with Model 407001

software and interface cable kit Operating

Temperature

32 to 122°F (0 to 50 °C)

Operating Humidity Max. 80% RH Power Supply Six (6) 1.5V ‘AAA’ batteries Power Consumption Approx. 30 mADC Weight 0.78 lb (355 g) including batteries & probe Dimensions Main instrument: 7.1 x 2.8 x 1.3” (180 x 72 x 32 mm)

Sensor: 0.5” (12mm) diameter

Telescope: 7’ (2.1m) maximum length with cable

Range Specifications

Units

Range Resolution Accuracy

m/s 0.2 to 20.0 m/s 0.1 m/s ±(3.0%rdg+0.3m/s)*

km/h 0.7 to 72.0 km/h 0.1 km/h ±(3.0%rdg+1.1km/h)*

ft/min 40 to 3940 ft/min 1 ft/min ±(3.0%rdg+59ft/min)*

MPH 0.5 to 45.0 MPH 0.1 MPH ±(3.0%rdg+0.67MPH)*

knots 1.0 to 31.0 knots 0.1 knots ±(3.0%rdg+0.58knots)*

*or, ±(1.0%FS+3d) whichever is greater

Temperature 32 to 122

F (0 to

0.1 oF and

C 1.5

F (0.8

Note: m/s: meters per second; km/h: kilometers per hour; ft/min: feet per minute; Knots: nautical miles per hour; MPH: miles per hour

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Model 407123 V5.2 2/2006

Meter Description

1. LCD display – Indicates air velocity and temperature readings, units of measure, low battery icon, and other user alerts

2. Push-buttons:

• POWER: Turn meter ON and OFF

• HOLD: Freezes the displayed reading

• C/F: Select the temperature units

• RECORD: Press to track the highest

(MAX) and lowest (MIN) reading

• RECALL: Displays MAX/MIN readings

• UNIT: Air velocity units of measure

• ZERO: Press to zero the display

(sensor cover must be closed)

3. Protective holster – Rubber jacket that surrounds the meter (must be removed to access battery compartment)

4. Battery compartment - Located on the lower back of the meter

5. PC Interface jack – Accepts a 3.5mm plug from a PC interface cable (cable and data acquisition software available using part number 407001)

6. Sensor input jack – Insert the sensor plug

7. Sensor opening – Air must flow through this opening for proper measurement

8. Telescoping sensor handle – Extends to 39” (1m)

9. Sensor protective cover – Slide DOWN to open when in use and slide UP to protect sensor when not in use (close the cover when zeroing the meter)

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Model 407123 V5.2 2/2006

Operation

Initialization and Zero The meter should always be zeroed at temperature before use using the ZERO button.

Do not rely on the initial zero display. Note: The meter does not display negative numbers. Open antenna to desired length.

1. Connect the sensor to the input jack on top of the meter and open antenna to desired length.

2. Turn on the meter using the Power button. The meter will perform a self-test during which the display will count down from 9999 to 0000.

3. Select the desired temperature units using the C/F select button. The LCD will reflect the selection.

4. Select the desired air velocity units using the UNIT button. The LCD will reflect the selection.

5. Place the sensor cover in the UP (ZERO) position.

6. Place the sensor in the area to be measured and allow a short time for the sensor to reach the temperature of the air under test.

7. Press the ZERO button to zero the meter.

Taking Measurements

1. Zero the meter as described above.

2. Slide the air velocity sensor cover down.

3. Place the sensor in the air current to be measured. Have the air flow meet the sensor

head in the direction of the white dot on the sensor head.

4. View the air velocity and temperature readings on the LCD Display. The large main

LCD display shows the Air Velocity reading. The lower LCD sub-display shows the temperature reading.

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Model 407123 V5.2 2/2006

MIN and MAX Function

1. To begin capturing the Minimum (MIN) and Maximum (MAX) readings, press the

RECORD button. The ‘REC’ icon will appear on the LCD.

2. Take readings as described previously.

3. Press the RECALL button to view the Maximum reading encountered since the

RECORD button was pressed. The ‘MAX’ display icon will appear along with the maximum reading.

4. Press RECALL again to view the minimum reading (MIN).

5. Press the RECORD button to exit this mode and return to normal operation.

Data Hold

To freeze the LCD display, press the HOLD button. The 'DH' display icon will appear on the LCD. Press the HOLD button again to return to normal operation (the 'DH' hold icon will switch off).

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Model 407123 V5.2 2/2006

Battery Replacement

When the low battery indicator (LBT) appears on the LCD or if the LCD does not switch on when the POWER button is pressed, replace the batteries.

1. Remove the protective rubber holster that encapsulates the meter.

2. Open the rear battery compartment by prying the compartment off with a flat-head

screwdriver or a coin.

3. Replace the six ‘AAA’ 1.5V batteries observing polarity.

4. Replace the battery compartment cover and the protective holster.

PC Interface

The meter is equipped with an RS-232 PC Interface jack at the top of the meter (next to the sensor input jack). This port is for use with the Extech Part Number 407001 Data Acquisition software and interface cable kit. Directions for use are supplied with the 407001 kit. The interface kit allows the user to take measurements and view/save the readings on a PC.

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Model 407123 V5.2 2/2006

Useful Equations and Conversions

Area equations

The volume of air flowing through a duct or vent can be determined by taking the area of the duct in square units (i.e. square feet) and multiplying this value by the measured linear velocity (i.e., feet per minute). This gives: ft/min x ft

= ft3/min (CFM)

Cubic equations

CFM (ft

/min) = Air Velocity (ft/min) x Area (ft2)

CMM (m3/min) = Air Velocity (m/sec) x Area (m2) 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 1.1523 1 km/hr 0.2778 54.69 0.54 1 0.6222 1 MPH 0.4464 87.89 0.8679 1.6071 1

A = pi x R

A = W x H

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Model 407123 V5.2 2/2006



Support line (781) 890-7440

Technical support: Extension 200; E-mail: support@extech.com

Repair & Returns: Extension 210; E-mail: repair@extech.com

Product specifications subject to change without notice

For the latest version of this User’s Guide, Software updates, and other

up-to-the-minute product information, visit our website: www.extech.com Extech Instruments Corporation, 285 Bear Hill Rd., Waltham, MA 02451

Warranty

EXTECH INSTRUMENTS CORPORATION warrants this instrument to be f ree 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 at (781) 890-7440 ext. 210 for authorization or visit our website 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.

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.