This standard specifies baseline environmental conditions under which transit rail car electronic equipment shall both operate and/or survive. Special requirements anticipated for applications that have environmental conditions outside these baseline conditions are neither covered nor intended herein. Environmental conditions include: temperature, humidity, atmospheric pressure, water, corrosive elements, and vibration/shock. These conditions depend upon equipment location such as under car, interior, truck mounted, and carbody mounted. The purpose of the standard is to provide a baseline for contract specifications, design and manufacture of electronic equipment to be supplied for transit rail cars to eliminate unnecessary variability in specifications, allowing manufacturers to provide consistent product lines that can meet the needs of the industry, save costs and improve reliability. New IEEE Standard - Superseded. Baseline environmental conditions under which transit rail car electronic equipment shallboth operate and/or survive are specified in this standard.