| 摘要 |
<p>A respirator comprising an outer mask (2) in which is defined a main volume (16) and an oronasal mask (4) located within the outer mask and defining a secondary volume (17). Air for breathing enters the mask (2) via a one-way valve (9) and filter (10). Exhaled air exits the mask (4) via an exhale conduit (5) fitted with an exhale valve (6). A conduit (11) is provided for the passage of air from the outer mask (2) to the oronasal mask (4). The conduit (11) is fitted with a one-way valve (12) and a filter (13). The filter (13) is such as to filter either particular or vapour challenges, or a mixture of these, as required.</p> |
