The instruments for measuring environmental noise shall meet the requirements for a class 1 instrument according to IEC 61672-1 and octave filters shall meet IEC 61260, Class 1. For long-term monitoring the monitoring station should be equipped in automatic system check. For both long-term and short-term measurements, meteorological parameters shall be measured. As a minimum requirement, wind speed, wind direction, relative humidity and temperature shall be measured.
As a part of the monitoring system, SvanPC++ software helps to analyse the measurement results for example to extract and verify noise events such as vehicle pass-bys (car, train, aircraft) with the use of audio recording and automatic event markers.
The ISO recommends that monitoring station is tested and calibrated by the ISO/IEC 17025 laboratory once in a year.