Knowledge base

Basics of acoustics


Noise is defined as all unwanted, unpleasant and annoying sounds that affect humans. Being harmful to life and health, noise is recognized as an important determinant of environmental quality.


TThe acoustic wave propagating in the elastic medium or the auditory sensation caused by this wave. It is assumed that the human can detect sounds with frequencies ranging from 16 Hz to 20 kHz. Low-frequency vibrations are referred to as infrasound while … read more

Basics of photometry

Accuracy class according to CIE and DIN 5032-7.

Maximum values ​​of basic errors for luxmeters depending on the accuracy class are included in the table below:



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Questions and Answers

QUESTION 1: How often should measurement instruments be calibrated?

ANSWER: SONOPAN recommends the calibration of measurement instruments at least once every 12 months. The frequency of calibration depends on many factors. The most important ones are the intensity and range of use, the risk of the exceedance of the exposure limit values as well as the costs of the possible corrective measures after the detection of the instrument deficiencies. As calibration … read more


Standards related to the field of acoustic and vibrations:

EN 61672 Electroacoustics. Sound level meters.

EN 61260 Electroacoustics. Octave-band and fractional-octave-band filters.

ISO 7196 Acoustics. Frequency-weighting characteristic for infrasound measurements.

EN 60942 Electroacoustics. Sound calibrators.

EN ISO 4871 Acoustics. Declaration and verification of noise emission values of machinery and equipment.

EN ISO 3744 Acoustics. Determination of sound power levels and … read more