"This standard provides minimum requirements for the construction@ performance@ and testing of portable@ transportable@ mobile@ and stationary electrical apparatus whose purpose is for the detection@ measurement and notification of toxic gas in air that are used to enhance the safety of personnel in commercial and industrial locations. NOTE 1 ?? Laboratory- or scientific-type analysis or process control performance requirements are not part of this standard. a) Residential locations are outside the scope of this standard. NOTE 2 ?? Performance requirements for detection of flammable (explosive) concentrations of toxic gas(es) are not the purpose of this standard. NOTE 3 ?? The user should be aware of environmental effects on both the apparatus and the toxic gas. The effects are not intended to be evaluated by this standard. Hereafter@ the term ""apparatus"" will refer to ""gas-detection apparatus."""