Abstract: Disclosed herein are representative embodiments of grade rods, grade-rod readers, and combinations thereof. In one exemplary embodiment, a grade rod is provided that has a reference surface extending along at least a portion of the rod. The reference surface includes two or more reference indicators spaced at substantially even intervals from one another. A reader unit is mounted to the rod (for example, slidably mounted). The reader unit includes one or more sensors positioned proximate to at least a portion of the reference surface of the rod. The sensors of this embodiment are configured to detect the motion of at least one of the two or more reference indicators relative to the sensors as the reader unit is moved along the reference surface. Other grade rod and grade-rod reader embodiments, as well as methods for using such embodiments, are also disclosed.

Abstract: An apparatus for producing a pair of beams of light at a desired angle to each other. A light emitter and any associated optics generate a first beam of light which is directed to a remote target. The target reflects the light back, which is detected by a light detector. Separately, a second light emitter and any associated optics generates a second beam of light at an angle to the first plane of light. The second light emitter and optics is on a support structure which is moveable with respect to the first structure, and in one embodiment shares the same axis as the first support structure for holding the first light emitter and its optics. An angle measuring device indicates the angle of the second light beam with respect to the first light beam. The angle is maintained by adjusting the first support structure to maintain the reflection of the first beam to the detector.