Harmonisation of the measurement of the optical properties of greenhouse cladding materials
Harmonisation des méthodes de mesures optiques des matériaux de couverture de serres
Résumé
The aim of an ongoing European SMT project named 'new testing methods for plastic films used as greenhouse covering materials' is the development of new testing methods for measuring the ageing and the condensation behaviour of plastic films used as greenhouse covering materials. The measurement of the ageing consist of determining the degradation rates of the important physical, optical and mechanical properties of the film exposed to realistic greenhouse conditions. Very little progress has been made during the last few years in measuring the water condensation behaviour of the greenhouse covering and to analyse the consequences like the influence on the light transmittance and the drip off of condensation drops from the covering material under greenhouse conditions. To be able to measure and judge both properties it is important that at first harmonisation is reached between the partners by measuring the most critical optical properties of greenhouse covering materials (this is one of the four harmonisation tasks in this project). This paper reports about this harmonisation.
L'objectif d'un contrat en cours SMT ' New testing methods for plastic films used as greenhouse covering materials' est le développement de méthode de mesures du vieillissement et des condensations. Le vieillissement est mesuré par la détermination de la dégradation des principales propriétés physiques et mécaniques du film. En vue de préciser si le vieillissement est important, il est nécessaire au préalable d'harmoniser les méthodes de mesure des propriétés optiques des films.