Extech 407766, 407744 Operating Manual

User’s Manual

Model 407744 and 407766
Sound Level Calibrators

Introduction

Congratulations on your purchase of Extech’s Sound Level Calibrator. Extech Calibrators
accommodate Sound Level Meters with 0.5” and 1” microphones. The Calibrator’s die-cast
aluminum housing is built for ruggedness and durability. The 407744 provides a 94dB
calibration output signal while the 407766 provides both 94dB and 114dB outputs. This
professional calibrator, with proper care, will provide years of safe reliable service.

Specifications

Output signals 407744: 94dB

Output signal accuracy 407744: ± 0.5dB;

Output signal frequency 1KHz sine wave
Accuracy of output signal frequency ± 5%
Compatible microphones sizes 0.5” and 1” microphones
Total Harmonic Distortion (THD) <2%@94dB, <5%@114dB (407766)
Operating temperature 32 to 122oF (0 to 50oC)
Power supply Two (2) 9V batteries
Power consumption Approx. 10mA DC
Battery check Status LED
Dimensions 2.2” diameter x 5.7” length (50 x 145mm)
Weight 0.75 lbs. (340g)

407766: 94dB and 114dB

407766: ± 0.5dB (94dB), ±0.8dB (114dB)

Page 2 Models 407744 & 407766 - Version 5.0 - May 2005