1
Outline
The pistonphone NC-72A is a sound calibrator that conforms to IEC 60942:2003 (JIS C
1515:2004) class LS/C and class 1/C specifi cations.
It uses a purely mechanical sound source with very low time-based variations which is
capable of producing a sound of constant pressure and frequency unaffected by envi-
ronmental changes (however, compensation of the output sound pressure level for static
[atmospheric] pressure changes is required). The NC-72A is suitable for use in research
institutions as calibration sound source for maintenance and management of acoustic
measurement systems.