Leveling instrument Bosch GOL 26 D Professional

The Bosch GOL 26 D Professional is a manual optical leveling instrument designed for precise height determination and transfer on construction sites and in open terrain. Built with a rugged metal housing and IP54 dust and water protection, it is suitable for outdoor use and portability. The instrument features a 36 mm objective aperture and 26x magnification, a 5/8" tripod thread and an integrated compensator for fine automatic leveling.

Advantages

The GOL 26 D Professional provides high precision with a maximum deviation of 1.6 mm over 30 m and reliable operation at distances up to 100 m. Its metal housing with IP54 rating increases durability under outdoor conditions. The optical system with clear crosshairs and a fast aperture ensures sharp and easily readable rod graduations, while the tool requires no power supply and is compatible with standard building tripods. The instrument is supplied with a lens cover, plumb bob, adjusting pin, Allen key and a locking carrying case for safe transport.

Suitable for

• Transferring and determining heights on construction sites
• Surveying tasks requiring long-distance accuracy up to 100 m
• Laying foundations, drainage and general site levelling
• Outdoor work in dusty or wet conditions where an IP54 rating is required

Key specifications

• Magnification: 26x
• Objective aperture: 36 mm
• Leveling accuracy: 1.6 mm / 30 m
• Effective range: up to 100 m
• Protection class: IP54 (dust and water protection)
• Tripod thread: 5/8"
• Power supply: none required (manual optical level)
• Accessories included: lens cover, plumb bob, adjusting pin, Allen key, locking carrying case

How to use

Mount the optical level on a standard building tripod using the 5/8" thread and roughly centre the bubble in the circular vial with the three leveling screws. Look through the penta prism and use the integrated target collimator to align the instrument with the leveling rod. Perform coarse horizontal alignment using the friction-coupled angular adjustment operated by the side adjusting screws. When the vial is level, the integrated compensator performs fine automatic adjustment. Read the rod values through the telescope using the crosshairs; the 26x magnification and 36 mm aperture provide a sharp image for easy reading.

Usage recommendations

Store and transport the instrument in the supplied locking carrying case to protect the compensator and optical components. For tripod setup, use a stable 5/8" building tripod (for example BT 160 Professional) and check bubble alignment before each series of measurements. Choose the appropriate model variant (D for degrees) when degrees measurement is required.