Specifies groups of environmental parameters and their severities to which products are subjected when mounted for stationary use at weatherprotected locations. Limited to those which may directly affect the performance of products. No special description of the effects of these conditions on the products is given. Environmental conditions directly related to fire or explosion hazards and conditions related to ionizing radiation are excluded. Any other unforeseen incidents are also excluded. Microclimate within a product is not included. BS AMD 7931 RENUMBERS THIS STANDARD TO BS EN 60721 PT3-3