This standard covers temperature and humidity environmental conditions for industrial process measurement and control equipment. Specifications for other environmental conditions are beyond the scope of this standard.

This standard establishes temperature and humidity classes for fixed (non-mobile) installations during normal operation (nonemergency conditions) or during transportation and storage.

The classes of temperature and humidity 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 pertain only to the environment external to the equipment which may affect the equipment externally or internally.

The effects of environmental conditions on safety, comfort, and performance of operating and maintenance personnel are not considered in this standard.

Purpose

The purpose of this standard is to establish uniform classifications of temperature and humidity conditions for industrial process measurement and control systems. This document is one of a series of standards on environmental conditions for process measurement and control systems.