Verification and Documentation of Measurement Points on Survey & Construction Sites
Reflective Smart Target Plates, Datums & Reflectors
As seen in Professional Surveyor Magazine - "Coming to a Structure Near You"
(This article appeared in the December 2008 issue of Professional Surveyor Magazine and is displayed with permission. Copyright 2008 by Reed Business Geo, Inc.)
Berntsen International, Inc., the top supplier of high quality surveying products, is the first United States source for Rothbucher Systeme's full line of permanent precision survey markers. Designed to facilitate precise building, site layout, and monitoring, all Rothbucher survey markers and control points are made of tough, UV resistant materials and are intended for discreet, long term, highly precise control monumentation.
The Rothbucher System includes 20 specialized markers for placement on buildings, bridges, towers, roads, railroad tracks, and anywhere else precise, repeatable control is needed. Rothbucher markers typically include a reflective surface for use with most total stations, and a bull's eye or level line (or ledge) for accurate targeting. When placed on building axes or other critical dimensions, Rothbucher control markers can be used by most of the trades associated with large construction projects. They can be attached to important reference points by adhesive, threaded inserts, or can be set directly into concrete. One set of markers can be attached to formwork, and leaves a negative impression in concrete that can then be used for an elevation reference during the life of the entire project. Another set has a built-in `roof' that protects the target from any concrete applied to the structure after control has been placed. This line of control monumentation has been well tested in European construction-they are standard in many countries-and most uses have been anticipated with specialty markers that are easily installed and designed to last.
Construction of the World Trade Center's Transportation Hub the "Oculus"
Rothbucher markers offer a number of advantages to surveyors and contractors who do construction layout. Because they are low profile, measurements are taken directly at the point of interest, rather than at a prism offset. Because they remain in place permanently, shots to Rothbucher control markers are repeatable and more accurate than prism shots. And of course they are safer: after placement, employees never have to return. So shots that are high up, in active construction areas or traffic, or otherwise unsafe or difficult to access, only need to be physically accessed once, and every shot from that point on can be from a safe, remote location.
The entire line of markers is inexpensive, with adhesive backed reflectors costing just a couple of dollars each, and ranging up to about $50 for permanent, heavy duty markers on galvanized steel bases. The adhesive reflective markers are a good way for construction layout professionals to give this innovative product a try. They are small, flat, highly reflective markers, with a bulls-eye, and most total stations will read them precisely at several hundred feet. Reflectorless total stations will read these markers at close to maximum distance. Since they are also quick to apply and easy to carry in a pocket or pouch, field crews are likely to give them a try, and will quickly realize that they save time and effort.
Whenever you think that you might be coming back to a point, you should consider placing permanent, convenient, Rothbucher Systeme markers. You'll start saving time and money on your very next visit.