Perform calibration of a sound level meter

For acoustic calibration of a sound level meter including the microphone, an acoustic calibrator or pistonphone is required.
● Sound calibrator NC-74
Provides all required functions for sound level meter calibration. Compact and lightweight unit is easy to use and requires no atmospheric pressure correction. Operates on two IEC LR6 (size AA) alkaline batteries, enabling continuous operation of at least 30 hours at room temperature.
Major features are as follows.
Standard compliance: JIS C 1515: 2004 class 1, IEC 60942: 2003 class1
Supported microphone diameters: 1 inch, 1/2 inch
Atmospheric pressure compensation: not required
Frequency: 1000 Hz
Sound pressure level: 94 dB

For acoustic calibration of a sound level meter including the microphone, an acoustic calibrator or pistonphone is required.
● Pistonphone NC-72A
This calibrator is suitable for use as a standard sound source in the laboratory, or for sound level meter calibration in the field.
It provides high calibration accuracy within ±0.15 dB,
and can be used over a wide temperature range (-10°C to +55°C,10% to 90% RH).
A barometer for atmospheric pressure compensation is supplied with the product.
Major features are as follows.
Standard compliance: JIS C 1515: 2004 (IEC 60942: 2003) class LS/C, class 1/C
Supported microphone diameters: 1 inch, 1/2 inch, 1/4 inch
Atmospheric pressure compensation: required (using supplied barometer)
Frequency: 250 Hz
Nominal sound pressure level: 114 dB