The Topcon RL-H5A is a self-leveling horizontal rotary laser designed for elevation control on construction sites. With an 800-meter working range, IP66 weatherproofing, and 100-hour battery life from D-cell batteries, it's one of the most durable and reliable horizontal lasers in the professional contractor market.
| Working Range | 800m diameter with LS-80L receiver |
| Self-Leveling Accuracy | ±10 arc seconds |
| Self-Leveling Range | ±5° (instrument must be within 5° of level) |
| Grade Capability | Horizontal only — no slope setting |
| Rotation Speed | 300, 600, or 1200 RPM selectable |
| Battery | D-cell × 4 (~100 hours at 600 RPM) |
| IP Rating | IP66 (dust and waterproof) |
| Weight | 2.5 kg (5.5 lb) |
| Operating Temperature | -20°C to +50°C |
| Included | LS-80L receiver, carrying case, batteries, manual |
The RL-H5A is a horizontal-only rotary laser — it projects a perfectly level 360-degree beam but cannot tilt to match a slope. This makes it the right tool for: transferring a known elevation across a site, verifying slab elevation, checking finished floor height during interior work, landscape elevation control, retaining wall height verification, and drainage verification at a single elevation.
It is NOT the right tool for slope grading — setting a parking lot at 2% cross-slope, grading a road subgrade at 3%, or any application where the ground must follow a specific slope rather than a flat horizontal plane. For slope grading, you need a dual-slope laser like the Topcon RL-HV2S.
The RL-H5A excels in situations where you need to know "is the ground at the right elevation?" — not "is the ground at the right slope?"
Move the receiver to the correct rod reading before checking each point. When the receiver shows on-grade, the bottom of the rod is at design elevation.
| Issue | Cause | Fix |
|---|---|---|
| Tilt error / won't self-level | Surface slope exceeds ±5° self-leveling range | Move tripod to flatter ground. Level the tripod legs manually before powering on. |
| Receiver can't find beam | Too far from instrument, dead receiver battery, obstruction | Check distance (max 400m radius), replace receiver batteries, clear line of sight between laser and receiver. |
| Battery low indicator | D-cell batteries depleting | Replace D-cell batteries. Use Energizer lithium D-cells in cold weather for significantly longer life. |
| Beam flickers or pulses | Dirty lens or window | Clean the laser window with a soft, dry cloth. Never use solvents or abrasives. |
| Intermittent receiver beep | Signal fluctuating | Reduce receiver sensitivity setting. Check for highly reflective surfaces (puddles, glass) causing interference. |
Calibrate monthly or after any impact or drop. The two-peg test checks whether the laser beam is truly horizontal across the full working range.
Use our Laser Calibration Check Calculator to calculate the error automatically from your two-peg test readings.
The Topcon RL-H5A is a horizontal-only self-leveling rotary laser for elevation control. Common uses: landscaping elevation checks, slab height verification, interior finish elevation layout, retaining wall height, drainage verification at a fixed elevation. It cannot set a slope angle. For slope grading applications (road subgrade, parking lot drainage, athletic fields), use the Topcon RL-HV2S or Leica Rugby 680 dual-slope lasers instead.
The RL-H5A projects a horizontal beam only — there is no slope setting. To use it for elevation control: (1) Set up near a benchmark. (2) Measure instrument height above benchmark. (3) Calculate instrument elevation (benchmark + HI). (4) Calculate rod reading (instrument elevation − design grade). (5) Set receiver to that rod reading. On-grade signal = ground is at design elevation. For slope grading, you need a dual-slope instrument.
The RL-H5A is compatible with all standard Topcon laser receivers: LS-80L (included with most kits) for manual grade checking; LS-100D for machine control mounting on dozers and graders. The instrument emits at a standard wavelength compatible with Topcon receivers. For guaranteed compatibility, use Topcon brand receivers. Third-party receivers may work but are not guaranteed.
The RL-H5A uses four D-cell alkaline batteries with approximately 100 hours of rated battery life at 600 RPM. In cold weather (below 32°F / 0°C), alkaline battery life drops significantly. Use Energizer Ultimate Lithium D-cell batteries in cold conditions — they outperform alkaline at low temperatures and still provide excellent life at normal temperatures. Always carry spare batteries on the job site.
Perform a two-peg test monthly or after any impact: (1) Set up exactly midway between two stakes 100 ft apart, record rod readings at both — they should be equal. (2) Move to within 5 ft of one stake, take rod readings at both stakes again. (3) Calculate the difference — tolerance is ±1.5mm per 10m. If the error exceeds tolerance, send to an authorized Topcon service center. Field adjustment is not recommended.
Log calibration dates, set expiry alerts, and include equipment records in as-built reports. Free for 14 days.