Abstract: The invention relates to a system and method for monitoring light using a photosensitive mast mounted on a support or machine. A light signal, such as a laser, is detected by the photosensitive mast which has a plurality of optical fibers distributed longitudinally along and completely around the mast. The optical fibers are of lengths which differ by very small amounts, thereby creating any desired resolution of the photosensitive mast. The optical fibers are connected to a collecting device for gathering the light signals and determining the position of the light measuring device relative to the rotating laser light source.

Abstract: A depth monitoring system includes a pair of inclinometer sensors mounted on the boom and on the dipper stick of a digging machine to measure electrically the angle of inclination of the boom and the dipper stick relative to the horizontal. Employing these two sensors, the position of the bucket connected pivotally to the free end of the dipper stick can be calculated by means of a simple geometric equation in which each trigonometric function is based on a single angle only. Additionally, preset and zero reference capabilities are provided.