Extech Instruments 451212 User manual

Page 1 Model 451212 Version 2.3 May 2003
INSTRUCTION MANUAL
Model 451212
Air Velocity MultiMeter Adapter
1. INTRODUCTION
Congratulations on your purchase of Extech’s Air Velocity Multimeter Adaptor. The 451212
connects to the mV input of a multimeter for displaying air velocity (knots, ft/min, km/hr, and
m/sec). This professional device, with proper care, will provide years of reliable service.
2. SPECIFICATIONS
Measurement Range Output Accuracy
0.4 – 30.0 meters/sec 1 mV per 1m/sec ± (2% + 0.1 mV)
1.4 – 108.0 kilometers/hr 1 mV per 1km/hr ± (2% + 0.3 mV)
80 – 5910 ft/min 1 mV per 100ft/min ± (2% + 0.2 mV)
0.8 – 58.3 knots 1 mV per 1 knot ± (2% + 0.2 mV)
Sensor Twisted vane arm with low friction ball bearing
Sensor cable 55” cable
Power 9V Battery (low battery indicator located on front panel)
Operating
Temperature &
Relative Humidity
Temp: 32 to 122oF (0 to 50oC); RH: 90% max.
Dimensions 100 x 50 x 25mm (3.9x2.0x1.0”); Sensor: 2.8” (72mm) diameter
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Page 2 Model 451212 Version 2.3 May 2003
3. METER DESCRIPTION
Refer to the diagram on the front of the manual for the items below.
1. Output Plugs
2. Function select switch
3. Low Battery indicator
4. ON/OFF switch
5. Sensor
6. Power status indicator
7. Battery Compartment (on rear)
4. OPERATION
Proper operation of this adaptor requires the use of a multimeter with a DC voltage
function with mV resolution and an input impedance > 10MΩ.
1. Insert the output banana plugs into the VOLTS (HI) and COM jacks of the multimeter.
2. On the multimeter, select the DC 200mV range. Select the next higher range if this
range is not available. If the meter is autoranging,
manually lock the proper range.
3. Set the adaptor function switch to the desired units.
4. Turn the adaptor on via the POWER switch.
5. For maximum accuracy, the airflow must enter the
vane on the side without the yellow dot (see diagram).
6. The multimeter directly indicates the air speed. Note
the examples in the table below:
Range Typical display Multiply by Air Velocity
Meters/sec 11.93 mV x 1 11.93 m/sec
kilometers/hr 11.93 mV x 1 11.93 km/hr
ft/min 11.93 mV x 100 1193 ft/min
knots 11.93 mV x 1 11.93 knots
5. BATTERY REPLACEMENT
1. Battery replacement is necessary when the Low Battery Indicator lights.
2. Open the battery cover (screw on rear of adaptor) and replace the 9V battery.
6. CALIBRATION / REPAIR SERVICES
Extech offers complete repair and calibration services for all of the products we sell. For
periodic calibration, NIST certification or repair of any Extech product, call customer
service for details on services available. Extech recommends that calibration be performed
on an annual basis to insure calibration integrity.
7. WARRANTY
EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in parts and workmanship for one
year from date of shipment (a six month limited warranty applies on 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 for authorization. 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.
Copyright ©2003 Extech Instruments Corporation.
All rights reserved including the right of reproduction in whole or in part in any form.
airflow
yellow
dot
Side view of Vane