The Spectra Precision DG711 is a single-axis grade laser built for machine control on excavators, motor graders, and scrapers. With a grade range of 0–25% and a self-leveling range of ±10%, the DG711 handles the full spectrum of earthwork grades from flat subgrade to steep cut slopes. This guide covers everything about the DG711 — specifications, typical applications, step-by-step setup, and how to keep your calibration documented with Sitemark.
The DG711 differs from horizontal rotary lasers (like the Spectra HL750) in one critical way: it projects the beam at a programmable grade angle rather than a flat horizontal plane. This makes it the tool of choice when the design surface is sloped — drainage channels, road subgrades, and any earthwork where a flat laser plane would require constant recalculation of target elevations at every station.
| Grade Range | 0% to 25% (single axis) | Covers flat to steep cut slopes |
| Grade Accuracy | ±0.5mm/m (±0.05% of grade) | At rated working range |
| Self-Leveling Range | ±10% | Instruments self-levels within ±10% of level |
| Working Range | 200m diameter with HR320 | Machine control applications |
| Beam Type | Red visible laser, 635nm | Use receiver-based detection outdoors |
| Rotation Speed | 600 rpm standard | Compatible with machine control receivers |
| Grade Setting | Digital keypad on instrument | Also settable via wireless remote |
| Wireless Remote | Available separately | Adjust grade from cab or receiver end |
| Battery Life | 80+ hours on AA batteries | Full work week without replacement |
| IP Rating | IP66 | Dust-tight, strong water jet resistant |
| Operating Temp | -20°C to +50°C | Full seasonal operation |
| Compatible Receivers | HR320, HR500 series | Machine control and hand-held use |
The DG711's 0–25% grade range covers the vast majority of earthwork grade control applications. Here are the most common uses on construction sites.
Mount the HR320 receiver on the excavator boom. Set the DG711 to the design channel slope (for example, 0.5% for a drainage ditch). The operator follows the laser plane through the cut without a rod person. The receiver shows exactly how far the bucket is above or below design grade in real time.
Set up the DG711 parallel to the road alignment at the design crown or cross-slope. The grader operator uses one or two HR320 receivers on the blade to maintain consistent subgrade elevation and cross-slope across the full road width. Reduces bladework passes and achieves tighter as-built tolerances.
On push-pull or open-bowl scrapers, the DG711 provides a grade reference for loading and spreading cuts. The scraper operator follows the laser plane during load, maintaining the cut at design slope. Most effective on large earthwork sites where multiple scrapers can share one instrument setup.
For complex drainage grading with variable grades, the DG711 wireless remote lets the operator adjust the grade setting from the machine cab as the design grade changes along the alignment — without stopping work to reprogram the instrument at the tripod.
Step-by-step procedure for setting up the DG711 for single-operator excavation grade control.
Locate the design grade percentage from your drawings. Set up the DG711 tripod at the edge of the work area where it has clear line-of-sight to the full machine travel path. Rough-level the instrument within ±10% (the self-leveling range). Power on and enter the design grade on the keypad. The display confirms the grade setting and self-leveling status.
Drive the excavator to a known benchmark elevation (a hub or existing grade stake). Lower the bucket to the benchmark elevation. Adjust the DG711 tripod height until the HR320 receiver on the boom reads on-grade. This calibrates the system — the receiver at this height corresponds exactly to the bucket at benchmark elevation. Record the setup in Sitemark.
Clamp the HR320 to the excavator boom stick using the adjustable pole bracket. Position it where the laser plane will intersect the receiver window at approximately mid-height of the detection window when the bucket is at design depth. Connect the cable to the cab display or pair via Bluetooth. The cab display should now show cut/fill deviation.
With the bucket on the benchmark and the HR320 reading on-grade, zero the cab display. Now the system reads directly in cut/fill — if the cab shows "+50mm", the bucket is 50mm high and the operator needs to cut deeper. If it shows "-25mm", the bucket is 25mm below design and the operator needs to raise the bucket slightly.
Periodically check the receiver against a hand-held rod and level shot to verify the system hasn't drifted. Log verification shots in Sitemark with the point location, design elevation, actual elevation, and deviation. This creates a documented as-built record of your excavation grade — valuable for inspector submittals and dispute resolution.
Grade lasers used in machine control applications are subject to more vibration and rough handling than survey instruments. The DG711 should be calibrated by a certified repair center at regular intervals — most contractors specify 6-month or annual calibration cycles depending on use intensity.
Between formal calibrations, perform a field check at the start of every significant job: set up the instrument at a known grade, shoot a series of points at known elevations, and verify that the receiver reads on-grade at each. Document the check in Sitemark — this creates a pre-job calibration record that protects you if grade disputes arise during or after construction.
Sitemark tracks calibration due dates for the DG711, HR320, and all other instruments in your fleet. When a calibration is coming due, you get an alert before the job — not an inspection finding after.
Add DG711 to Sitemark →Calibration tracking, grade shot documentation, and as-built PDFs for machine control contractors using the DG711 and compatible receivers.
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