Pistonphone NC-72B

Pistonphone A standard Sound source that Generates a constant sound pressure of dB at Hz * 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.