MEASUREMENT OF SMOKE PRODUCTION OF LOW SMOKE CABLES BY MEANS OF PRESENT AND FUTURE TEST METHODS

摘要

During the last decades, we have observed a growing demand for so-called LS (Low Smoke) cables. Such a label could not be restricted to halogen free cables, e.g. some fuoropolymer cables, thanks to their low fuel load and rate of combustion, might belong to this category. More recently, the decision to include cables in the European Construction Products Directive has led to the need of more sensitive method for the measurement of smoke production. Beside the current most widespread method (known as the 3-m cube) with its pass/fail criterion, new methods have been developed, based on dynamic measurement. This has permitted some advances in the measurement of the smoke production rate (SPR) for cables. Nonetheless, it remains questionable whether even these new methods enable a reliable discrimination of LS cables since uncertainty is high for low SPR levels. Typical results and possible difficulties for the smoke classification of LS cables are presented here.