Terminology description of gas alarm

LEL: Chinese means lower explosion limit, which refers to the lowest concentration of combustible gas mixed with air and exploded under ignition conditions.

Ppm: one ten thousandth of gas concentration, ※ 1%= 10000ppm.

Vol%: refers to the volume concentration ratio of gas. Response time: When the concentration of the test gas changes instantaneously, it takes time for the indicated value to be controlled within a specific range of the final value.

Allowable concentration: refers to the concentration that will not adversely affect the health of almost all workers if the concentration of the substance in the air is lower than this value when workers work in places where they are exposed to harmful substances. This concentration is recommended by Japan Industrial Hygiene Society.

Intrinsically safe explosion-proof structure: this refers to the explosion-proof structure confirmed by public institutions through ignition tests and other tests. The electric spark or high-temperature parts generated by this structure will not ignite explosive gas under normal and accident conditions.