Establishes uniform classification of airborne contaminants for industrial process measurement and control systems, Specifications for other environmental conditions are beyond the scope of this standard. This standard establishes airborne contaminant clases for fixed (nonmobile) installations during normal operation (nonemergency conditions) or during transportation and storage. The clases of environmental conditions stated in this standard are suitable for use in activities related to process instrumentation; including design, manufacturing, sales, installation, test, use and maintenance. These classes may also be used as a guide when establishing requirements for environmental control of buildings or other protective housings for industrial process measurement and control systems. These classifications concern only the environmentexternal to the equipment. Conditions inside the manufacturer's enclosure are outside the scope of this standard. The effects of environmental conditions on safety, comfort, and performance of operating and maintenance personnel are notconsidered in this standard.