This user manual introduces the features and use methods of Extech 407744 and 407766 sound level calibrators.
This manual provides instructions for the Extech Model 407744 and 407766 sound level calibrators. These devices generate specific decibel outputs (94dB and/or 114dB) at 1kHz to calibrate sound level meters equipped with 0.5-inch or 1-inch microphones. The units feature a die-cast aluminum housing designed for durability and reliability.
| 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 |
| Compatible microphones sizes | 0.5" and 1" microphones |
| Total Harmonic Distortion (THD) | <2%@94dB, <5%@114dB (407766) |
| Operating temperature | 32 to 122 oF (0 to 50oC) |
| Power supply | Two (2) 9V batteries |
| Dimensions | 2.2" diameter x 5.6" length (50 x 127mm) |
| Weight | 0.75 lbs. (340g) |
| Standards | IEC 60942 1997-11 class 2 |
The Model 407744 provides a 94dB output, while the Model 407766 provides both 94dB and 114dB outputs.
These calibrators accommodate sound level meters with 0.5-inch and 1-inch microphones.
Move the function switch to the 'Battery test' position; the Battery status LED should illuminate if the battery is OK.
The accuracy of the output signal frequency is ± 5%.