Extech Extech 461891 Manual

User’s Guide

Contact Tachometer

Model 461891

• Measures from 0.5 to 19999 rpm

• Min/Max Memory Recall

• Cone, funnel, surface attachments included

• Quartz crystal time base

99 Washington Street
Melrose, MA 02176

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

Visit us at www.TestEquipmentDepot.com

Back to the Extech 461891 Product Page

Introduction

Congratulations on your purchase of Extech’s Digital Tachometer. This professional meter,
with proper care, will provide years of safe reliable service.

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

FAX [phone] - TestEquipmentDepot.com

Specifications

General Specifications

Circuit

Custom one-chip LSI microprocessor circuit

Time base Quartz crystal

Display 5-digit multi function LCD display

Measurements Rotation Speed 0.5 to 19,999 rpm

Surface Speed 0.2 to 6560 ft/min.

0.05 to 1999.9 m/min

Memory Last and Max/Min readings

Sampling Time 1 second

Operating Temperature/RH 32 °F to 122 °F (0 °C to 50 °C) / <80% RH

Power Supply 4 x 1.5V AA batteries

Power Consumption Approx. 10 mA

Weight 0.62 lb (280 g) including batteries

Dimensions 8.2 x 2.8 x1.5" (208 x 72 x 37 mm)

Accessories Cone rpm adaptor, funnel rpm adaptor, surface speed

Range Specifications

rpm 0.5 to 19,999 rpm 0.1 rpm (0.5 to 999.9 rpm)

ft/min 0.2 to 6560 ft/min 0.1 ft/min (0.2 to 999.9 ft/min)

m/min 0.05 to 1999.9 m/min 0.01 m/min (0.05 to 99.99 m/min)

Range Resolution Accuracy

test wheel, and carrying case

1 rpm (over 1000 rpm)

1 ft/min (over 1000 ft/min)

0.1 m/min (over 100 m/min)

+

(0.05% rdg +1d)

@23+

± (1% rdg + 1 digit)

5oC

2

461891 Ver. 1.9 7/02

Front Panel Description

1 Shaft with cone adapter attached

2 LCD display

3 Measure button

4 Function select switch

5 Memory button

6 Funnel adapter attachment

7 Surface wheel adapter attachment

Operation

RPM Measurement

a) Slide the Function Switch to the "RPM" position.

b) Install the appropriate RPM Adapter on the Shaft

c) Press the Measure button while lightly pressing the RPM adapter against the

central opening of a rotating shaft in proper alignment. Release the Measure
button when the display stabilizes (about 1 to 2 seconds).

Surface Speed Measurement

a) Slide the Function Switch to "ft/min" or "m/min"

b) Attach the Surface Speed Wheel to the Shaft

c) Press the Measure button and hold the surface speed wheel against the device

being measured. Release the Measure button when the display stabilizes.

Memory Recall

The last value and last max and min values obtained before releasing the Measure
button are automatically stored by the meter. These memorized values can be
displayed by pressing the Memory button as described below:

a) Press once and hold - the last value is displayed followed by the "LA" icon

b) Press again and hold - the maximum value is displayed followed by the "UP"I con

c) Press again and hold - the minimum value is displayed followed by the "dn" icon

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

FAX [phone] - TestEquipmentDepot.com