A standard Sound source that Generates a constant sound pressure of 114 dB at 250Hz

・Conforms to IEC 60942 : 2017 class LS/M and class 1/M
・Supports exact frequencies (251.19 Hz)＊
・Exact frequencies have been adopted due to revisions to certification and inspection regulations of the Measurement Act of 2015.
・Allows calibration with precision of ±0.10 dB
・Can also be powered by NiMH batteries
・Usable as a standard sound source in laboratories or as a calibration sound source for sound level meters on site.