The scope of this recommended practice encompasses the range of environments which influence the performance and reliability of the electronic equipment designed for heavy duty on and off road vehicles@ as well as any appropriate stationary applications which also use these vehicle derived components. A few examples of such vehicles are on and off highway trucks@ trailers@ buses@ construction equipment and agricultural equipment including implements. Purpose: This document is intended to aid the designer of commercial vehicle electronic systems and components by providing guidelines that may be used to develop environmental design goals. Specific test requirements are to be agreed upon by the customer and supplier.