Dial gauge

A mechanical pressure gauge, comprising:

• a dial gauge having:
• a dial plate having a dial face including angularly spaced markings indicating pressure values;
• a pointer disposed at a front side of the dial plate and angularly moveable over the dial face with respect to the markings so as to indicate a reading;
• an illumination source arranged to emit illumination light and disposed below a central region of the dial plate, wherein the illumination source is visually obscured such that it cannot be viewed directly from above the dial plate;
• and
• an integrally formed optical light guide extending from underneath the dial plate to the front side of the dial plate and arranged to guide illumination light from below the dial plate to the front side of the dial plate so as to illuminate the dial face from above, the light guide comprising:
• an annulus disposed underneath the dial plate and radially outwardly extending from a light input formed by the radially inner surface of the annulus, the illumination source being disposed within the central opening of the annulus;
• and
• a cylindrical wall optically coupled to the annulus and extending around the periphery of the dial plate and having a part projecting above the dial plate forming a light output.