Patent ID: 7513055
Filing Date: 2009-04-07
Classification: G01C

Abstract:
1. A slope level comprising: at least one transparent arced tube, the tube defining an inner space containing a liquid therein and a bubble of gaseous fluid disposed in the inner space within the liquid; a frame comprising: a fill member positioned between the front face and the back face of the frame, the fill member forming a groove shaped to accommodate the arced tube and to allow for viewing of the arced tube from at least the front face or the back face through the corresponding aperture or apertures in the frame the fill member including filler material comprised of a plurality of voids defined by members; and at least one clear cover comprising transparent material positioned between the fill member and a side of frame comprising an aperture; wherein the at least one clear cover is configured to extend across the aperture to protect the arced tube; wherein the arced tube has a first end and a second end and the arced tube defines a pinnacle point between the first end and the second end; wherein the first and second ends of the arced tube are in closer proximity to the first planar measurement surface than the pinnacle point; and wherein the arced tube comprises glass that filters UV (ultraviolet) radiation.