ČSN P CEN/TS 16272-7

The purpose of insertion loss measurements is to have an indication of the "efficiency" of the complete installation in attenuating noise from a technical point of view, as is usually done with calculations. The insertion loss is not intended to compare products; in fact, it is site-dependent, so that the same product may give different results when installed on different sites. In order to be representative, these measurements need to be done in well-defined conditions regarding: - the noise source (number and type of trains, speed, etc.); - the meteorological window; - the measurement time; - the reference time, i.e. the time over which the measured insertion loss is evaluated based on the measurement results. When it is not possible to carry out measurements before the construction of the noise barrier, an "equivalent" site is used for the "before" measurements. The assessment of insertion loss limiting values is out of the scope of this Technical Specification.