Environmental Factors Influencing a Technical Installation

External effects endangering a technical installation may originate from natural phenomena or from the influence of civilization . In general, technical installations with a high hazard potential are protected against such effects. 

For evaluation of the potential hazard to the technical installation or to the staff, it will be necessary to conduct a comprehensive site analysis. This should include the listing of all potential sources of danger within the installation itself, on the plant premises as well as in the installation s immediate environment. Sources of danger in the vicinity may include depots for flammable liquids, depots for chemicals, pipelines above or below ground level carrying explosive or harmful substances, and busy air lanes (e.g., lanes of approach to an airport). 

The dynamic process of pressure propagation can be described by the laws of the conservation of mass, momentum, and energy. From these laws, a theoretical representation may be derived for simple cases, as described below for pressure waves with small pressure amplitudes. Such a pressure wave can be described approximately by the following equation  

Fj is the pressure difference P-P against the environmental pressure c is the speed of sound in the atmosphere and x, y, z are the space coordinates for the propagation of the pressure waves. For a wave which spreads 

For trinitrotoJuene (TNT) used as an explosive, extensive measuring results are available for the various pressure wave effects. These measurements demonstrate that the pressure waves for various amounts of explosives follow a law of similitude. The pressure amplitudes of explosion waves and other parameters, for a distance related to the amount of energy, the so-called reduced distance have one and the 

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The interlinking of cybernetics and the science of safety results from the fact that technical installations are operated and monitored by human beings who are involved within the effective range of that same installation. They are using the machine but are likewise exposed to its dangers. Human behavior as well as the behavior of the machine, on the other hand, are dependent on the conditions of their environment. The environment, in turn, is often influenced by them in various ways, e.g., by the production of waste, sewage, noise, and alien substances into the air. Man, on the other hand, is able to influence these environmental factors. Each and every technical installation is thus embedded in a man-machine-environment-system characterized by mutual interaction (Figure 3.12). 

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