CAN/CSA-Z433-M92 (R1997)

1.1 Outlines the details of construction, marking, and testing of portable electrical instruments for sensing the presence of toxic gas(es) and/or oxygen concentrations in air. These instruments may be used in Class I hazardous locations and gaseous mines in accordance with the Rules of the Canadian Electrical Codes, Parts I and II. 1.2 This Standard applies to battery-operated instruments having a battery of a nonrechargeable or a rechargeable type. 1.3 This Standard applies to single or multifunction portable gas-detection instruments intended to provide an indication, alarm, or other output function, the purpose of which is to minimize or prevent the possibility of exposure to an oxygen-enriched or oxygen-deficient atmosphere, or a toxic gas. 1.4 This Standard does not apply to laboratory or scientific gas-detection instruments used only for analysis or measurement, or instruments used solely for process control purposes. 1.5 This Standard does not apply to the central monitoring, data acquisition, or otheCr similar systems to which the gas-detection instrument may be connected.