| 摘要 |
511,551. Gas-detectors. CEAG, Ltd., and PLUMMER, R. J. March 26, 1938, No. 9375. [Class 1 (i)] A gas-detector of the Wheatstone bridge type is mounted between the battery casing a and the bull's-eye lantern h of a miner's lamp. The resistances d are housed in cells e', e<2>, the former being sealed and the latter provided with flame-proof inlet and outlet. The scale m of the ammeter b may be illuminated by a supplementary lamp (not shown) which is switched on when the main lamp is switched off, this being effected by turning the bezel ring h surrounding the lantern. The detector is switched on by pressing a push-button c. |
