Abstract: A receiver for a laser transmitter for use in surveying, comprising a housing and a sensor module pivotably mounted on the housing so that, by pivoting the sensor module relative to the housing, the device can detect a laser signal coming from sources at various angles to the housing. Also, a battery receptacle comprising a housing which defines a cavity and an opening at one end of the cavity for receiving a battery. First and second recesses are formed at the other end of said cavity and are shaped to receive terminals on a battery which is inserted in the cavity. First and second electrically conductive springs are mounted in the first and second slots, respectively. A door is mounted on the housing to close the opening and to retain a battery in the cavity.

Abstract: Apparatus for projecting a laser beam to provide simultaneously a stationary reference beam and a moving reference beam, which rotates in a plane normal to the stationary reference beam, includes a beam diverting arrangement for intercepting a primary beam and for splitting the beam into the two reference beams. The beam diverting arrangement includes first and second deflecting elements which deflect the beam by 90.degree. with respect to the primary beam. A portion of the primary beam, striking the first deflecting element, passes through the element and is shifted slightly by refraction. This shift is compensated by a third beam deflecting element which is fully transmissive, and which refracts the stationary reference beam into alignment with the primary beam. By cutting the first and third deflection elements from the same sheet of material and reorienting the elements appropriately, slight deviation from parallelism in the opposing surfaces of the sheet of material are compensated.