The rugged and compact design makes it well suited for both laboratory and field use. The design ensures a stable and uniform sound power output with unique long-term stability. The reference sound source Nor278 is designed to produce a stable and uniform sound power output with unique long-term stability. The high sound power output makes it ideal for sound power measurements in a noisy environment. The rugged, but yet portable and light weight construction is perfect for field us as well a laboratory use. Every effort is made in the design to ensure a uniform frequency response and optimum directional characteristic well inside the requirements in ISO 6926.

• Substitution and Juxtaposition methods for determination of sound power of noise sources according to ISO 3747
• Comparison method for determination of sound power of noise sources according to ISO 3741, ISO 3743-1, ISO 3744 and 3747.
• A weighted Sound power output : 93 dB re 1 pW (50 Hz line frequency)
• Sound power 50 – 20.000 Hz: 94 dB re 1 pW (50 Hz line frequency)
• Fulfills ISO 6926 for reference sound sources in the extended frequency range 50 – 20.000 Hz.
• Individual calibrated (accredited calibration optional)
• Long-term stability
• Weight 18,6 kg
• Rugged