A surveyor's tool to facilitate the measurement of the elevation of an invert within a manhole includes a rod with a dimensioning along its length. The tool further includes a slide moveable with respect to said rod. The slide includes a pair of opposing arms, the arms extending from opposite sides of the slide and extending perpendicular to the length of the rode. The slide further includes an inclinometer for measuring the angle of incline of the rod. Using the length of the rod extending into the manhole and the angle of the rod as determined by the inclinometer the depth of the invert can be calculated.
An apparatus for measuring the location and annular orientation of pipe inverts and other features in manholes. An elongate, telescoping rod is supported centrally in the manhole opening by a pivot assembly that permits the rod to both rotate in the horizontal plane and pivot in the vertical plane. A laterally-extending foot member on the lower end of the telescoping rod is inserted into the openings of the inverts for measurement. Electronic angle sensors record the length and orientation of the rod member at each measurement point, from which the location and angular orientation of the invert opening or other feature is then calculated.
