Digital levels by Leica Geosystems.

Late last year, the New Jersey Department of Transportation (NJDOT) made history when they purchased 18 NA2002 digital levels from Leica Geosystems of Norcross, Ga. One of them bore the serial number 10,000.

This announcement demonstrates that digital leveling has won widespread acceptance in the construction and surveying community. Leica Geosystems patented the first digital levels a little over 10 years ago. According to Mark Cummock, geodesy support engineer for Leica Geosystems, “The technology is more efficient and accurate than conventional optomechanical levels and is rapidly becoming the preferred technique for a wide range of tasks, such as running in sewer lines, grading roadside curbs and gutters, and staking out site grading for excavation.”

Eric Kraehenbuehl, manager of survey services for NJDOT, agrees. “With the digital level, we have achieved time savings of up to 50 percent because so much of the operation—from reading the staff to computing the results—is automated,” Kraehenbuehl says. His department now uses digital levels for all aspects of highway surveying, for second- to fourth-order leveling, topographic surveying and a wide range of construction surveying tasks.

Now, Leica has introduced its second generation of digital levels, the Leica DNA03 and DNA10. These lightweight 2.8 kg digital levels offer improved optical mechanical systems, a proven user-friendly menu and large LC-display surrounded by a modern ergonomic design. Each of these systems also includes the same or better accuracy as previous models. Using a standard rod, the systems are able to achieve an accuracy of 1.0 mm with the DNA03 and 1.5 mm with the DNA10 within three seconds from a range of 1.8 meters to 110 meters. With an invar rod, the accuracy increases to 0.3 mm with the DNA03 and 0.9 mm with the DNA10.

New Jersey-based Medina Consultants, P.C., a civil engineering and land surveying consulting firm specializing in transportation, is one of the first to take advantage of this new generation system. The company has used digital levels for the past four years on projects such as a multi-billion dollar rail/tunnel project connecting Queens and Manhattan in New York. According to Mike King, deputy director of surveying services at Medina, “In general, digital levels give us more confidence in the results compared to conventional systems. Added to this, the automated data processing features cut office work to a minimum.”

The new digital levels promise to improve Medina’s efficiency even more. King says he is most excited about the incorporation of the PC-card reader. “We have GPS and robotic systems that use card readers. Now with digital levels incorporating the same data storage device, it just makes it that much easier to transfer data to a computer back at the office for analysis,” he says. For Medina, these new digital levels are playing an active part in a new 8-mile subway line project that involves the construction of a new underground subway line linking the east side of Manhattan to the financial district in New York, an area destroyed by the September 11th terrorist attacks.