Extech 461891 Operating 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

Introduction

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

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