The aim of this Nordtest method is to form a basis for the evaluation of Personal Gas Monitors for safeguarding persons in underground locations, closed vessels, tunnels, mines, etc. In this method a monitor means a portable (hand-held) electronic instrument which gives audible and visual alarm for the user when exposed to concentrations above the alarm limit of the following gases:
a) toxic gas: Hydrogen sulphide H2S, Carbon monoxide CO 6.
b) flammable gas
c) oxygen deficiency (not for use in medical practice).
The method covers battery-operated monitors either for detecting one particular gas or more gases by the same monitor.
The test method concerns the primary performance characteristics of the monitors mentioned above and the stability of the performance characteristics against influences from the environment.
Additionally to the tests in this Nordtest method National authorities may have regulations which include further tests for example concerning electrical safety in hazardous areas.