"This Standard addresses the details of construction@ performance@ and testing of portable@ mobile@ and stationary electrical instruments. These instruments may be used to monitor for the presence of ammonia gas concentrations in air. Parts of the instruments may be installed or operated in hazardous (classified) locations. This Standard applies to mains-connected instruments rated at 250 V nominal or less@ and to portable@ mobile@ and stationary type instruments powered by a battery(ies). This Standard applies to instruments suitable for use in an ambient temperature range of at least -10 ??to 50 ??(14 ??to 122 ??. This Standard addresses ammonia gas detection instruments intended to provide a warning of the presence of potential hazards in the concentration ranges up to 500 ppm. Hereafter@ the term ""gas detection instrument"" refers to an ammonia gas detection instrument. This Standard does not address laboratory- or scientific-type ammonia gas detection instruments used for analysis or measurement in process control and process monitoring applications@ instruments intended for residential purposes@ or instruments with full-scale gas concentration ranges less than 25 ppm or greater than 500 ppm. NOTE ?C The user should specify instrumentation that will provide a higher level of accuracy than the minimum tolerances of this Standard if required by the application risk. Purpose This Standard provides minimum performance requirements of electrical instruments for the detection of ammonia gas (NH3)@ in order to enhance the safety of personnel. This Standard establishes user criteria for the installation@ operation@ and maintenance of ammonia gas detection instruments."