Extech 407740 Operating Manual

User's Guide

Digital Sound Level Meter
Model 407740

Introduction

Congratulations on your purchase of the Extech 407740 Digital Sound Level Meter. This
device measures sound in decibels (dB). Useful features include A/C Weighting,
Fast/Slow Response Time, and Maximum Reading HOLD. Careful use of this meter will
provide years of reliable service.

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 [phone] 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.

Specifications

Display 2000 count multi-function LCD

Input Signal Range ‘A’ Weighting: 30 to 130dB

‘C’ Weighting: 30 to 130dB

Response Time Fast: Response = 125ms; Slow: Response = 1s

Resolution 0.1 dB

Standards Compliance ANSI and IEC Type 2

Accuracy (at 23

Frequency 31.5 to 8,000Hz

Microphone Electric condenser microphone, 0.5" (12.7mm)

Range Selector Switch 30 to 80dB, 50 to 100dB, 80 to 130dB

External Calibrator Use Extech model 407744 or 407766

Analog Output Signal AC: 0.5Vrms (full scale of selected range)

Analog output impedance 600 ohms

Analog Output Terminal 3.5mm phone jack

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

Operating Humidity Max. 90% RH (0° to 35°C)

Power Supply 9V battery

Dimensions / Weight 10 x 2.8 x 1.1” (255 x 70 x 28mm) / 10 oz. (280 g)

o

± 5 o C) ±1.5dB at 1KHz (94dB)

DC: 0.3 to 1.3VDC, 10mV/dB



Support Hotline [phone]

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

Website: www.extech.com

2

Model 407740 version 1.6 8/05