The Spectra Precision DG813 Digital Theodolite delivers reliable, fast angle measurement for survey crews, layout contractors, and construction professionals who demand accuracy without sacrificing field efficiency. Built as a modernization upgrade over analog instruments, the DG813 combines a bright digital readout, refined optical system, and rugged construction to keep your crew productive from the first setup to the last shot of the day.
Overview & Jobsite Applications
Whether you're establishing control points on a commercial build, performing boundary surveys, or laying out structural grids, the DG813 is engineered to handle the demands of active jobsites. Its digital angle display eliminates interpolation errors common to vernier scales, while its compact form factor makes it easy to transport between setups. The instrument integrates smoothly into existing field workflows, making it a practical upgrade for teams already operating with conventional theodolites or transitioning from optical instruments.
Key Specifications
- Angle measurement type: Digital electronic display
- Horizontal and vertical circle reading: Electronic incremental encoding
- Minimum reading: 1" / 5" (selectable)
- Accuracy: ±2" (5 mgon)
- Telescope magnification: 30x
- Shortest focusing distance: 1.0 m (3.3 ft)
- Leveling: 3-screw leveling base with circular and plate bubble
- Dual-axis display: Horizontal and vertical angles shown simultaneously
- Battery life: Up to 40 hours continuous use on standard batteries
- Operating temperature: -20°C to +50°C (-4°F to +122°F)
Key Features
- Large, backlit LCD display for easy reading in low-light or bright sun conditions
- Left/right angle measurement modes with hold and repeat functions
- Vertical angle reference: Zenith, horizontal, or percentage grade display modes
- Coaxial tangent screws for precise horizontal and vertical fine adjustment
- Built-in optical plummet for accurate instrument centering over control points
- Dust- and splash-resistant housing for demanding outdoor environments
- Compatible with standard tribrach and 5/8" x 11 tripod systems
- Audible and visual bubble level confirmation for faster setup
Job Applications
Construction Layout: Use the DG813 to establish building lines, column grids, and anchor bolt patterns with repeatable angular precision — reducing rework and keeping structural trades on schedule.
Boundary & Topographic Survey: Reliable horizontal and vertical angle readings make the DG813 a capable instrument for traverse work, boundary retracement, and topo data collection when paired with a total station workflow or conventional tape measurement.
Utility & Pipeline Layout: Set alignment angles and grade references for underground utility corridors, drainage structures, and pipeline easements where consistent angle control is critical.
Monitoring & Quality Control: Perform periodic structural or earthwork monitoring checks using the DG813's repeatable angle measurement capability to verify that elements remain within design tolerance over time.
Compatible Accessories
- Heavy-Duty Aluminum Tripod for Theodolites
- Optical Tribrach with Plummet
- Surveying Prism Pole Kit
- Carrying Case for DG813
- Replacement Battery Pack
Related Guides
- How to Set Up a Digital Theodolite on a Construction Site
- Theodolite vs. Total Station: Which Instrument Is Right for Your Crew?
- Angle Measurement Basics for Layout Contractors
- Spectra Precision Instrument Comparison Guide
Frequently Asked Questions
- What is the angular accuracy of the Spectra Precision DG813?
- The DG813 delivers an angular accuracy of ±2 arc-seconds (5 mgon), making it suitable for construction layout, boundary survey traverses, and general angle measurement tasks where tight tolerances are required.
- Does the DG813 measure distances?
- No — the DG813 is a digital theodolite designed specifically for angle measurement. It does not include an EDM (electronic distance measurement) module. For distance measurement, it is typically paired with a separate EDM or used alongside conventional taping methods.
- Is the DG813 compatible with standard survey tripods?
- Yes. The DG813 mounts on standard 5/8" x 11 threaded tripods and is compatible with optical tribrachs, allowing it to integrate with most existing survey equipment setups in the field.
- Can the DG813 display grade or percent slope readings?
- Yes. The vertical angle display on the DG813 can be switched between zenith angle, horizontal angle, and percentage grade modes, giving contractors flexibility when working on slope-sensitive applications like drainage or road grading.
