Sokkia B40A-25 Automatic Level — Built for the Jobsite
The Sokkia B40A-25 automatic level is a rugged, field-proven optical instrument designed for contractors, surveyors, and construction crews who need dependable height and grade measurements every day. Featuring 25X magnification, a pendulum compensator for rapid horizontal alignment, and a compact body that stands up to jobsite conditions, the B40A-25 delivers the precision and durability professionals demand. Whether you're setting foundations, controlling utility grades, or running topographic surveys, this instrument is engineered to keep your work on level.
Overview and Jobsite Applications
The Sokkia B40A-25 belongs to Sokkia's trusted B-series lineup, a range of automatic levels widely used across civil construction, land development, and infrastructure projects. The self-leveling compensator eliminates the need for constant manual adjustment, allowing crews to set up faster and stay productive across long workdays. The instrument's sealed optics and durable housing make it well-suited for dusty sites, road construction zones, and outdoor surveying in variable weather conditions. It pairs with standard leveling rods and tripods for complete, ready-to-work configurations.
Key Specifications
- Model: Sokkia B40A-25 (SKU: 1009572-53)
- Magnification: 25X
- Objective Lens Diameter: 36 mm
- Shortest Focusing Distance: 0.3 m (1 ft)
- Compensator Type: Pendulum (magnetic damping)
- Compensator Range: ±15'
- Compensator Accuracy: ±0.5"
- Circular Level Sensitivity: 8'/2 mm
- Image: Erect
- Weight: Approximately 1.5 kg (3.3 lbs)
- Standard Compliance: ISO 9001 quality manufacturing
Key Features
- 25X magnification for sharp, long-range target acquisition on standard leveling rods
- Automatic compensator with magnetic damping ensures fast, accurate self-leveling after coarse setup
- Erect image system for intuitive rod reading without image inversion
- Compact, lightweight body reduces fatigue during all-day field work
- Large objective lens gathers ample light for clear sighting in overcast or low-contrast conditions
- Standard tribrach mount compatible with common surveying tripods and accessories
- Smooth tangent screw for fine horizontal aiming adjustments
- Durable construction suitable for demanding outdoor environments
Job Applications
Foundation Layout and Floor Elevation Control: Use the B40A-25 to transfer benchmark elevations across a building pad and verify that footings, slabs, and structural elements meet design grades before concrete placement.
Utility and Pipeline Grade Control: Maintain precise slope and invert elevations for storm drains, sewer lines, and water mains. The compensator's accuracy keeps grade consistent over long runs where small errors compound quickly.
Road and Site Grading: Set cut-and-fill stakes for earthwork crews, check subgrade elevations against design plans, and verify finished surface grades before paving operations begin.
Topographic and Differential Leveling: Run level loops across a project site to establish control benchmarks or collect spot elevations for as-built surveys and quantity calculations.
Compatible Accessories
- Aluminum Surveying Tripod — Heavy-Duty Adjustable
- Fiberglass Grade Rod — 13 ft / 4 m
- Sokkia Instrument Carrying Case
- Plumb Bob and Line Set
- Rod Level Bubble for Vertical Rod Alignment
Related Guides
- How to Set Up and Use an Automatic Level on a Construction Site
- Auto Level vs. Laser Level: Which Is Right for Your Project?
- Understanding Compensator Accuracy in Optical Levels
- How to Run a Differential Level Loop for Site Benchmarks
Frequently Asked Questions
- What is the difference between the Sokkia B40A-25 and other B-series models?
- The B40A-25 is distinguished by its 25X magnification and ±0.5" compensator accuracy, making it one of the more precise optical levels in the B-series lineup. Other models in the series may offer lower magnification or a wider compensator range suited to less demanding applications.
- Does the Sokkia B40A-25 require batteries or external power?
- No. The B40A-25 is a fully optical automatic level. It requires no batteries or external power source. The self-leveling compensator operates mechanically using a pendulum and magnetic damping system, making it ready to use anywhere without charging or power management concerns.
- What type of tripod is compatible with the B40A-25?
- The Sokkia B40A-25 uses a standard 5/8" x 11 tribrach thread mount, which is compatible with the vast majority of surveying and construction tripods on the market. Both aluminum and fiberglass tripods in fixed-head or adjustable-leg configurations will work with this instrument.
- Can the B40A-25 be used for long-distance sightings on large construction sites?
- Yes. The 25X magnification and 36 mm objective lens allow clear, accurate rod readings at the distances typical on most construction and civil engineering sites. For very long sighting distances, using a high-contrast rod target and ensuring proper focus will maximize reading accuracy.
