acoustic calibrator / for sound level meters / portable / rugged

The Sound Calibrator Type 4231 is a handy and portable device for calibration of sound level meters and other sound measurement equipment. Its battery-operated and pocket-sized design features a high stable level and frequency with calibration accuracy of ± 0.2 dB. It comes with a leather protecting case but there's no need to remove it to use the calibrator. This advanced instrument has a sound pressure independent of microphone equivalent volume and the calibrator automatically switches off once the microphone is removed. It is very easy and convenient to use that you can have a definitive calibration in 5 seconds.