scope:

Introduction

The corrosive effect of complex ambient conditions on materials determines in many cases the length of the functionality of an object and/or the changes in its visual appearance and as a consequence the time a repair or restoration becomes necessary. The influences range from climatic conditions, entry of natural or anthropogenic pollutants to mechanical or biological wear [1]. The interactions of the various types of influences are mostly complex. The measurement of individual parameters, such as the impacts of climate or atmospheric pollutants, provides only limited information on the damage caused. In order to be able to characterise the difficult to comprehend processes taking place on the objects, studies of effects are necessary (compare VDI 3955 Part 1 and Part 2).

The present guideline addresses the exposure of thin plates of natural stone under natural conditions. This procedure rounds up the glass sensor method described in Part 2 of this guideline. While the glass sensor method provides information on the impact of ambient conditions on the surface of a dense, nonmetallic material, the exposure of thin stone plates characterises the effects on dense and porous minerals of known composition. This guideline provides the fundamentals for studying the effects as required by Article 47 of the Federal Air Pollution, Noise, and Vibration Control Law (Bundesimmissionsschutzgesetz) and Article 2 Section 1, Number 2 of the Law on Environmental Impact Testing (Umweltverträglichkeitsprüfung). The guidelines objective is to standardise the procedures which have been applied in various German federal states and some European countries [2].