| 摘要 |
<p>There is disclosed a dial gauge comprising a dial plate 12 having a dial face 14 including angularly spaced markings indicating values; a pointer disposed at a front side of the plate and angularly moveable over the face with respect to the markings to indicate a reading. An illumination source 20 is arranged to emit illumination light and is disposed below the dial plate. The gauge further comprises a light guide (22, Fig 3) arranged to guide light from below the dial plate to the front side of the plate to illuminate the dial face from above, this may be both from the centre and from the edge of the dial plate. There is also disclosed a mechanical pressure gauge comprising a dial gauge and a breathing apparatus comprising a cylinder of breathable gas fluidically coupled to a pressure gauge configured to display the pressure of the breathable gas.</p> |
