Sound Calibrator Nor1256

Nor1256 is a small battery-operated precision class 1 microphone calibrator conforming to IEC 60942 and ANSI S1.40. 
The combination of two different levels and two different frequencies allow both level linearity and frequency linearity to be verified. In addition the sound calibrator measures the environmental conditions; air pressure, temperature and humidity.
Each calibrator is supplied with an individual accredited calibration certificate.

The all-digital design with a quartz controlled signal generator ensuring a frequency stability not yet seen an any calibrator on the market today. The reference microphone and control circuit together maintain a constant sound pressure level inside the calibration coupler and automatically adjust for changes in load volume, temperature, humidity, and barometric pressure. The selected level and frequency is clearly indicated on the OLED display. Each calibrator is supplied with an individual accredited calibration certificate.

The Nor1256 is setting a new standard for sound calibrators by offering two levels and frequencies in combination with measurement of ambient temperature, relative humidity and static pressure. The generated sound pressure levels are 94dB and 114dB (re. 20 µPa) at 250Hz and 1000Hz. The twin frequencies and levels enables linearity and frequency response check of the microphone and allows a wide range of calibration applications to be covered by one unit.

The calibration level, frequency and environmental parameters are displayed on a high contrast OLED display. The calibrator can be used directly on 1” microphones and smaller microphone sizes via adapters. At power on the calibrator generate 114dB@1000Hz. A push on the dB button toggles between 94 and 114dB. Likewise a push on the Hz button toggles between 1000 and 250Hz. The °C/°F button displays the ambient pressure, temperature and humidity.


  • Conforms to EN/IEC 60942 : 2017 Class 1, and ANSI S1.40–2006
  • Ultra-stabile silicone reference microphone
  • All-digital quartz controlled signal generator
  • Fully compensated for static pressure, humidity and temperature
  • Sound pressure independent of microphone equivalent volume
  • Robust, compact and battery operated.
  • 114 and 94dB @ 1000 and 250 Hz
  • Built in display
  • Measurement of humidity, temperature and static pressure

The diagrams below show typical influence of variations in the environmental parameters: temperature, humidity and air pressure. The reference conditions are 23ºC (73,4ºF), 50% relative humidity and an air pressure of 101,325 kPa.

Typical sensitivity to temperature:

Nor1256 Sound Calibrator typical sensitivity to temprature

Nor1256 Sound Calibrator typical sensitivity to temprature

Typical sensitivity to air pressure:

Nor1256 Sound Calibrator typical sensitivity to air pressure

Nor1256 Sound Calibrator typical sensitivity to air pressure

Typical sensitivity to humidity:

Nor1256 Sound Calibrator typical sensitivity to humidity

Nor1256 Sound Calibrator typical sensitivity to humidity 

General Sound calibrator class 1 according to EN/IEC 60942 : 2017 Class 1 and ANSI/ASA S1.40-2006 (R2011).

Microphone size: 1/1” and below.
Calibrator frequency (@ Reference conditions): 251.19±0.30 Hz and 1000 ±1.00 Hz
Generated Sound Pressure Level relative to 20μPa (@ Reference conditions): (114.0±0.2)dB and 94.0±0.2)dB
Distortion: Max 2.0%
Stabilizing time: 20 seconds
Sensitivity to environmental conditions: As specified for IEC 60942 class 1 / ANSI S1.40.

Environmental range for specified operation:

Temperature: -10ºC to +50ºC / 14ºF to 122ºF
Relative humidity: 25% to 90%
Air pressure: 65 kPa to 108 kPa
Display type and resolution: Mono-colour OLED graphical display – 128×64 (WxH)

Additional specifications for the built in ambinet measurement sensors:

Temperature range: -10ºC to +50ºC or 14ºF to 122ºF
Resolution / Accuracy: 0.1ºC / ±2ºC or 0.1ºF / ±2ºF
Atmospheric pressure: 65 kPa to 108 kPa; Resolution 0.1kPa; Accuracy ±0.4 kPa, (for temperature above 0ºC)
Relative humidity: 0% to 100%; Resolution 1%; Accuracy ±4%, (for temperature above 0ºC and humidity in the range 25% to 85%)
Power off: By power switch or when microphone is removed (may be deactivated)
Battery type: 2 x LR03 alkaline batteries (AAA-size)
Battery life: > 10 hours
Battery low: Automatically switching off if battery voltage too low
Weight: 125g / 0.28lb
Size ( LxWxH ): 97×51.5×41 mm / 3.8×2.0×1.6 “

Accessories included:
(may vary if supplied as part of a Sound level meter kit):

  • 1/2” microphone adapter Nor4583
  • Accreditated calibration
  • 2 x AAA batteries, instruction manual
  • Leather pouch Nor1345.

Accessories available:

  • 1/4” microphone adapter Nor4589