Instruments are centered over the vertex by suspending a plumb bob beneath the instrument or by using an optical plummet.
Procedures for Centering an Instrument The procedures for centering an instrument over a point will vary depending on whether the instrument uses a plumb bob or an optical plummet.
TIP Although the optical plummet will be used to center the instrument, a plumb bob can be used to center the tripod.
The PLS product line includes laser line levels, laser plumb bobs
, rotary lasers, laser detectors, optical levels, tripods, and grade rods.
The company specializes in the sale of laser levels and laser level accessories of all types including rotary lasers, laser line levels, laser plumb bobs, laser distance meters, laser detectors, torpedo lasers, laser level tripods, grade rods and now automatic levels.
They have also added money saving builders level kits and packages which includes the automatic level, a tripod, a grade rod, and a plumb bob.