Bruel and Kjaer 4227 Overview
- Conforms to IEEE-269, IEEE-661 and ITU-T P.51.
- Accurate level and frequency response calibration is easily done using a Brüel & Kjær ½" microphone placed in the supplied calibration jig
- Accurate simulation of human voice field
- Quality control testing of frequency response and distortion of telephone transmitters and close-talking microphones
- Continuous SPL of 100dB 25mm from lip ring
- Low distortion
- Built-in overload protection circuit
