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Overview
The Spectra Precision GL422N-27 Dual Grade Laser Package represents the professional solution for complex grading projects requiring independent slope control in two perpendicular directions. This complete system combines Spectra's advanced dual-slope laser technology with the HL760 digital receiver, inches-graduated leveling rod, and heavy-duty tripod—everything needed to tackle parking lots, building pads, drainage channels, and site preparation work where precise multi-directional grading is critical.
Unlike single-slope lasers that limit you to simple planar work, the GL422N-27 enables simultaneous X and Y axis grade control with independent slope settings from -10% to +10% in each direction. The included HL760 receiver provides digital grade readout with millimeter-level precision, while the complete package arrives job-ready with professional mounting and measurement accessories. Whether you're establishing proper drainage flow, creating level building foundations, or preparing athletic fields with multiple grade requirements, this dual-slope system delivers the control and accuracy demanded by professional contractors and site preparation specialists.
Designed for durability in harsh construction environments, the GL422N-27 features IP67-rated protection against dust and water intrusion, rugged construction capable of withstanding 1-meter drops, and Spectra's renowned reliability that keeps you productive through demanding job site conditions.
Key Specifications
- Grade Capability: Dual-slope with independent X and Y axis control
- Slope Range: -10% to +10% in both directions simultaneously
- Accuracy: ±1/16 inch at 100 feet (±1.5mm at 30m)
- Working Diameter: Up to 2,600 feet (800m) with HL760 receiver
- Self-Leveling Range: ±5 degrees with automatic calibration
- Rotation Speed: 600 RPM for optimal visibility and range
- Environmental Protection: IP67 rating (dust-tight and water-resistant)
- Drop Resistance: Survives 1-meter drops onto hard surfaces
- Power Source: Rechargeable NiMH battery system
- Battery Runtime: Up to 60 hours continuous operation per charge
- Operating Temperature: -4°F to 122°F (-20°C to 50°C)
- Weight: 10.6 lbs (4.8 kg) laser unit only
What's in the Kit
- GL422N-27 Dual Grade Laser: Main rotating laser transmitter with dual-slope capability and carrying case
- HL760 Digital Receiver: LCD display receiver with visual and audible grade indicators, rod clamp included
- Inches-Graduated Leveling Rod: Professional telescoping grade rod with clear imperial markings for elevation measurement
- Heavy-Duty Tripod: Adjustable-height tripod with quick-setup legs and 5/8 x 11 mounting thread
- RC402N Remote Control: Wireless remote for slope and rotation speed adjustment from up to 300 feet away
- Rechargeable Battery Pack: High-capacity NiMH battery with charging cradle and AC adapter
- Alkaline Battery Tray: Backup power option using standard D-cell batteries
- User Documentation: Comprehensive operating manual with setup and calibration instructions
Job Applications
- Parking Lot Construction: Create multi-directional drainage slopes that direct water toward collection points while maintaining proper grade transitions. The dual-slope capability allows you to establish crown centerlines while simultaneously grading toward perimeter drains—critical for preventing standing water and ice formation in commercial parking facilities.
- Building Pad Preparation: Establish level foundation areas while maintaining perimeter drainage grades. Set the pad surface perfectly level for concrete placement while programming subtle slopes at pad edges to direct water away from the structure—eliminating the need for multiple laser setups and reducing foundation preparation time.
- Drainage Channel Installation: Configure complex channel gradients where water flow direction changes or where channels intersect at angles. The independent X-Y slope control enables proper flow velocity maintenance throughout directional transitions, preventing sediment accumulation and ensuring efficient water evacuation.
- Athletic Field Grading: Construct sports fields requiring crowned surfaces with perpendicular drainage slopes. Establish the longitudinal crown for field runoff while simultaneously creating cross-slopes for sideline drainage—achieving the multi-directional grading that prevents field flooding and maintains playable surfaces.
- Roadway and Pathway Cross-Slopes: Install proper crowned road surfaces with consistent side-to-side drainage while maintaining longitudinal grade requirements. The dual-slope system eliminates layout complexity by controlling both the roadway crown and the forward slope simultaneously, ensuring proper water sheet flow off pavement surfaces.
- Site Excavation and Grading: Prepare construction sites requiring multiple elevation transitions and drainage patterns. Reduce setup time on complex site work by programming both directional slopes at once, maintaining productivity on projects where traditional single-slope lasers would require constant repositioning and recalibration.
Compatible Accessories
- HL450 Economy Receiver: Budget-friendly single-display receiver for basic grade indication applications
- HL700 Rod-Mounted Receiver: Compact receiver with simplified controls for straightforward grading work
- CR700 Machine Receiver: Heavy-duty receiver designed for dozer and grader blade mounting with rugged construction
- RC602N Remote Control: Extended-range remote with enhanced display for advanced slope programming
- Metric Grade Rods: Centimeter-graduated leveling rods for projects using metric measurements
- Laser Detector Card: Handheld target card for quick laser beam location and alignment verification
- Extended Battery Packs: Additional rechargeable batteries for multi-day projects without charging access
- Elevator Tripod: Precision elevation tripod with fine-height adjustment for exacting setup requirements
Related Guides
- How to Choose the Right Rotary Laser for Your Application
- Setting Up Dual-Slope Lasers for Complex Grading Projects
- Understanding Laser Receiver Accuracy and Features
- Maintaining and Calibrating Construction Lasers for Accuracy
FAQ
- What's the difference between single-slope and dual-slope lasers?
- Single-slope lasers create a tilted plane in one direction only, suitable for simple drainage or sloped surfaces. Dual-slope lasers like the GL422N-27 can tilt independently in two perpendicular directions simultaneously, enabling complex grading applications like crowned parking lots, building pads with perimeter drainage, or intersecting drainage channels. If your project requires water to flow in changing directions or needs both level and sloped areas in perpendicular planes, dual-slope capability is essential.
- How far can I work from the laser with the HL760 receiver?
- The HL760 receiver provides a working radius of up to 1,300 feet from the laser (2,600-foot diameter coverage area) under normal conditions. Actual range depends on ambient light conditions, with reduced range in direct bright sunlight. For maximum range, the system works best during overcast conditions or during early morning and late afternoon hours. The digital display shows signal strength to help you determine when you're approaching range limits.
- Can I use this laser for interior concrete floor leveling?
- Yes, the GL422N-27 excels at interior floor leveling work. You can set it to level mode (0% slope in both directions) for flat floor applications, or program subtle drainage slopes for floors requiring water flow toward drains—common in commercial kitchens, car wash facilities, or industrial spaces. The precision accuracy of ±1/16 inch at 100 feet meets or exceeds requirements for most commercial concrete floor specifications.
- Is the system difficult to set up and program slope angles?
- The GL422N-27 features intuitive controls with a clear digital display showing slope percentages in both axes. Basic setup involves mounting on the tripod, positioning at your reference point, allowing self-leveling to complete (about 30 seconds), then using the control panel or RC402N remote to input your desired slopes. The user manual includes slope calculation charts, or you can input known slope percentages directly. Most operators become proficient with setup within one or two uses, and the remote control allows adjustments without returning to the laser.
