Specifications : 4231 Brüel & Kjaer Acoustic Calibrator for sound level meter : NF EN/CEI 60942 (2003), Class LS and Class 1, Calibrators acoustic, Nominal Sound Pressure Level : 94.0 dB ±0.2 dB (main SPL) or 114.0 dB ±0.2 dB ref 20 μPa at 1 kHz ±0.1%
