Patent ID: 7975393

Claim:
A spirit level comprising an oblong body comprising a planar base for resting, in use, on a surface whose level is to be determined, a planar top surface substantially parallel to the planar base, and a planar front surface substantially perpendicular to the planar base and planar to surface, the spirit level further comprising levelling means comprising a vial filled with a sufficient liquid that an air bubble is formed within the vial, the spirit level comprising indicia relative to which the bubble moves as the orientation of the spirit level is altered so as to indicate the orientation of the spirit level, optical means being provided on the spirit level and operative to provide an image indicative of the position of the bubble relative to the indicia, a portion of the level being formed with a recess that extends from the top surface and the front surface into the body of the level and comprises at least one surface comprising the optical means, the at least one surface facing the vial and having light reflecting properties, the reflected light forming the image indicative of the position of the bubble relative to the indicia, the at least one surface being planar, the plane of the at least one surface being inclined to both the top and the front surfaces of the level.