Reference Sound Source Nor278

Reference sound source for sound power measurements.

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 6926:2016.


  • Comparison method for determination of sound power of noise sources according to ISO 3741, ISO 3743-1 and ISO 3747.

  • A weighted Sound power output: 94 dB re 1 pW (50 Hz line frequency)
  • Sound power 50 Hz – 20 kHz: 94 dB re 1 pW (50 Hz line frequency)
  • Fulfils ISO 6926:2016 (ANSI S12.5-2016) for reference sound sources in the extended frequency range 50 Hz – 20 kHz.
  • Delivered with accredited calibration certificate
  • Long-term stability
  • Weight 18 kg (50 Hz) /  24,5 kg (60 Hz)
  • Rugged

Each unit is carefully assembled and individual tested. To enhance the level of quality and traceability of your measurements every unit is accredited calibrated by the Norsonic Calibration Laboratory (NCL) in accordance to ISO 6926:2016. This service is also offered for periodic re-calibration.

Norsonic Calibration Laboratory is an accredited laboratory to work in compliance with ISO/IEC 17025 in carrying out calibration of acoustical equipment for measuring noise (sound level meters, microphones, dosimeters and acoustical calibrators), accelerometers, tapping machines and reference sound sources. The  accreditation is recognized internationally through European and global multilateral agreements in more than 40 countries around the world made through the International Laboratory Accreditation Cooperation – ILAC. Thus the Norwegian Accrediting body has established that Norsonic calibrations are internationally accepted as being carried out in an accredited laboratory.


Device type: Reference sound source according to ISO 6926:2016 for extended frequency range 50 Hz – 20 kHz.
Power Supply: 200 – 240 volt (50 Hz) / 110 – 115 volt (60 Hz)
Power consumption: <750 W (typical 650 watt)  (50 Hz) / 900 W (typical 800 watt) (60 Hz)
Fuses: 10A – slow blow (220 V) / 20A – slow blow (110 V)
Sound power output each 1/3-octave frequency band: >75 dB re 1 pW  (50 Hz) / >77 dB re 1 pW (60 Hz)  in each 1/3-octave bands in the range 100 Hz to 10 kHz.
A-weighted sound power output: 94 dB (typically) (50 Hz) / 97 dB (60 Hz)
Weight: 18 kg (50 Hz) / 24,5 kg (60 Hz)
Height exclusive handle: 396 mm
Height inclusive handle: 464 mm
Diameter: 283 mm
Temperature: -25° to 50°C. Above 35°C intermittent use only.
Humidity: Up to 90 %, non-condensing.

Complience: IEC 6926:2016, ANSI/ASA S12.5-2016
CE-mark indicates compliance with: Machinery Directive, EMC Directive and Low Voltage Directive.