User Manual

2
407744 & 407766 - V5.1 – 04/10
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
407766: 94dB and 114dB
Output signal accuracy 407744: ± 0.5dB;
407766: ± 0.5dB (94dB), ±1.0dB (114dB)
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 122
o
F (0 to 50
o
C)
Power supply Two (2) 9V batteries
Power consumption Approx. 10mA DC
Battery check Status LED
Dimensions 2.2” diameter x 5.6” length (50 x 127mm)
Weight 0.75 lbs. (340g)
Standards meets IEC 60942 1997-11 class 2
Standards Meets IEC 60942 1997-11 class 2