Extech Instruments 461893 User Manual

User's Manual

Digital Photo Tachometer

Model 461893

Model 461893 Ver. 1.3 Oct. 2002

2

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 ext. 210 for authorization or visit our website at www.extech.com (click on ‘Contact Extech’ and go to ‘Service
Department’ to request an RA number). 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.

Introduction

Congratulations on your purchase of the Extech 461893 Photo Tachometer. This device

provides non-contact measurements over a wide range (5 to 100,000 RPM). A reflective

mark on the object to be measured is used as a target for the meter's integral light beam.

Careful use of this meter will provide years of reliable service.

Specifications

General Specifications

Meter circuitry

Custom one-chip LSI microprocessor

Time base Quartz crystal

Display 5-digit (99999 count) 0.4" (10mm) multi-function LCD

Measurement 5 to 99,999 RPM in 2 ranges

Range select Automatic

Data Recording LAST / MIN / MAX readings stored for later recall

Sampling time 1 second (over 60 rpm)

Target distance 2 to 6" (50 to 150mm) depending on ambient light

Operating Temperature 32°F to 122°F (0°C to 50°C)

Power Supply 4 x 1.5V 'AA' batteries

Power Consumption Approximately 150 mA

Weight 8.8 oz. (250 g) including battery

Size 6.7 x 2.8 x1.5" (170 x 72 x 37mm)

Accessories Reflective tape (23") and carrying case

Range Specifications

Measurement Range Resolution Accuracy

RPM 5 to 999.9 RPM

1,000 to 99,999 RPM

0.1 RPM

1 RPM

+(0.05% + 1 digit)

+

(0.05% + 1 digit)

Model 461893 Ver. 1.3 Oct. 2002

3

Meter Description

1. Photo source

2. LCD Display

3. Memory record button

4. Battery compartment on rear

5. Measure button

Meter Operation

RPM Measurements

1. Apply a small piece of reflective tape to the object under test as shown below.

2. Point the meter's photo source at the tape on the object and press the Measure button.

Hold the meter from 2 to 6" (50 to 150mm) from the reflective tape depending on

ambient light.

3. Check that the Monitor icon flashes on the LCD indicating that the meter is sensing a

reflection from the tape. If the monitor does not appear check that the light source is

hitting the reflective tape at a 90

o

angle.

4. Release the Measure button when the display stabilizes (2 seconds approx.). Note the

LCD RPM reading.

5. If the RPM value is < 50, apply additional pieces of reflective tape (four pieces are

shown below). Divide the LCD reading by the number of reflective tapes to compute

the actual RPM (Actual RPM = Reading / 4).

Photo Tachometer

Rotating object

Reflective tape

Light source

and reflection

Support Hotline [phone]

Tech support: Ext. 200; Email: [e-mail]
Repair/Returns: Ext. 210; Email: [e-mail]

Website: www.extech.com

Memory Record and Recall

The meter automatically records the Mini mum and Maximum readings. These represent

the lowest and highest readings measured from the moment the Measure button is

pressed to the moment it is released. The Last reading is also recorded; this is the last

measurement taken before the Measure button is released. These stored readings can be

displayed on the LCD using the Memory button as described below:

1. Press once and hold: The Last reading is displayed followed by "LA"

2. Press again and hold: The Maximum value is displayed followed by the word "UP"

3. Press again and hold: The Minimum value is displayed followed by "dn"

Special Measurement Considerations

1. The non-reective area of the object under test must always be greater than the

reective tape area.

2. If the shaft of the object under test is re ective, it should be covered with black tape or

paint before attaching reective tape.

Battery Replacement

The low battery indication appears as "LO" on the display. To replace the batteries:

1. Slide the rear cover o the battery compartment in the direction indicated by the arrow.

2. Replace the four 1.5V 'AA' batteries and the battery compartment cover.

3. Remove the batteries if the instrument will be stored for long periods of time.

Calibration and Repair Services

Extech oers complete repair and calibration services for all of the products we sell.
For periodic calibration, NIST certication 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.

Copyright ©

2002 Extech Instruments Corporation.

All rights reserved including the right of reproduction in whole or in part in any form.

more infor for Extech 461893

Phone: [phone]

Email: [e-mail]

Web. www.airconcern.co.uk

Air Concern Ltd, Building 173 Curie Avenue Harvell Didcot, Oxfordshire