Second hand Bruel&Kjaer 4231 Sound level calibrator class 1

Second hand Bruel&Kjaer 4231 Second hand checked and calibrated.   Specification: Conforms to EN/IEC 60942 (2003) Class LS and Class 1, andANSI S1.40–2006 Robust, pocket-sized design with highly stable level andfrequency Calibration accuracy ±0.2 dB 94 dB SPL or 114 dB SPL for calibration in noisyenvironments Extremely small influence of static pressure and temperature Sound pressure independent of microphone equivalentvolume 1 kHz calibration frequency for correct calibration levelindependent of weighting network Fits Brüel & Kjær 1″ microphones (1/2″, 1/4″ and 1/8″microphones with adaptor) Switches off automatically when removed from themicrophone  Package includes: Calibrator, leather case, 1/2" Adapter, calibration report