| 摘要 |
<p>1497760 Lamps A AHLSTROM OSAKEYHTIO 28 Oct 1975 [20 Dec 1974] 44371/75 Heading F4R A lighting fitting comprises a ballast casing in gaseous communication with a lamp chamber and a filter casing releasably attached to the ballast casing and forming a gas passage between the interior and the exterior of the fitting, the filter casing containing at least one filter element for retaining fine particulate material and at least one element for absorbing or adsorbing gas.</p> |
