1. Scope

1.1 This Standard applies to process measurement and control equipment that has been designed and assessed for use either in, or in conjunction with, Class I, Division 2 hazardous locations as defined in the Canadian Electrical Code, Part I. The principles may also be applied to other similar types of equipment.

1.2 This Standard also covers portable battery-powered equipment.

1.3 The requirements of this Standard are based on consideration of ignition in locations made hazardous by the presence of explosive atmospheres under normal atmospheric conditions. For the purposes of this Standard, normal atmospheric conditions are generally considered to be
(a) an ambient temperature of -50 to +40°C;
(b) an oxygen concentration of approximately 21% by volume; and (c) a pressure of 86 to 106 kPa.
Note: Equipment specified for atmospheric conditions beyond the above limits are subject to investigation.