To Next PageTo Next Page
Need help?Do you have a question about the Johnson 40-6646 and is the answer not in the manual?
Details on how to install batteries, including cover removal, insertion, and replacement.
Advice on maximizing laser beam visibility in bright conditions.
Procedure to verify the vertical accuracy of the laser beams.
Procedure to verify the horizontal accuracy of the laser beams.
Details on how to install batteries, including cover removal, insertion, and replacement.
Advice on maximizing laser beam visibility in bright conditions.
Procedure to verify the vertical accuracy of the laser beams.
Procedure to verify the horizontal accuracy of the laser beams.
The Johnson Self-Leveling 3 Dot Laser, Model No. 40-6646, is a precision tool designed for various leveling and plumb layout applications. This Class II laser product is manufactured to comply with CRF 21, parts 1040.10 and 1040.11, as well as international safety rule IEC 285.
The primary function of this device is to simultaneously project three laser beams (front, up, and down) to accurately check plumb and level. This makes it ideal for tasks such as plumbing walls, setting drywall top and bottom track, and transferring reference points from floor to ceiling. The laser is also useful for setting a common level height for electrical boxes or switches, hanging photographs, setting fence posts, pipe stubs, or electrical conduit to a common height, and ensuring collinearity. It can be used for leveling pipes and plumbing, setting pitch on drainage pipes, installing wainscoting, installing wallpaper, checking the level or pitch of a poured concrete floor, and checking the square of windows and doorways.
The tool features a magnetic dampening compensation system that quickly and accurately stabilizes the pendulum, ensuring it stays level even with nearby vibrations on the job site. An important usage feature is the visual out-of-level indicator, which alerts the user when the tool is beyond its ±5° self-leveling range. In such cases, the laser will flash, and the status light will turn red. Once the instrument is adjusted within its self-leveling range, the laser will self-level, the status light will turn green, and the laser light will stop flashing and remain solid. The device also includes a locking compensator that helps protect the tool's inner mechanisms during transport and when not in use.
To power on the laser, slide the locking compensator up. This action unlocks the compensator, allowing the laser to self-level. The status light will illuminate, and the three laser beams (up, front, and down) will be emitted. To power off the unit and engage the pendulum lock, slide the locking compensator down. This ensures the laser can be safely transported.
For battery installation, the battery cover is located at the back of the tool. It can be removed by pressing the release tabs on the left and right sides and pulling the cover back. Two "AA" alkaline batteries should be inserted according to the polarity indicated inside. When replacing the cover, seat the bottom edge first, then pivot it up, pressing the release tabs to clear the housing as it closes. Always ensure the locking compensator/power switch is in the locked position before changing batteries. Only alkaline batteries should be used.
To enhance beam visibility in bright conditions or near windows/outside walls, users can work towards the laser, use a freestanding target (sold separately), or wear laser glasses (sold separately). It is crucial to remember that laser glasses enhance visibility but should never be used to stare into the beam or as safety glasses, as eye damage may result.
This Self-Leveling 3 Dot Laser is a precision tool and requires careful handling. It should not be exposed to shock vibrations or extreme temperatures. For extended storage (more than 3 months), the batteries should be removed to prevent damage from deterioration. The unit should be kept dry and clean, especially the laser output window. Any moisture or dirt should be removed with a soft, dry cloth. Harsh chemicals, strong detergents, or cleaning solvents should not be used on the unit.
It is the user's responsibility to ensure proper maintenance and to conduct periodic test measurements to verify the instrument's accuracy and consistency, especially if it has been exposed to extreme temperatures or moisture. The instruction manual provides detailed steps for checking plumb and level accuracy. For plumb accuracy, the laser is placed on a flat surface in a tall room (20' or higher is ideal, or a mirror can be used for shorter rooms). The plumb up and down beams are marked at various 90-degree rotations to establish four points on the ceiling. The laser is in tolerance if the diameter of the circle formed by these points is equal to or smaller than specified values (e.g., 3/64" for a 10' ceiling).
For level accuracy, the instrument is placed on a level surface, such as a tripod, between two walls at least 25' apart. The laser is pointed at Wall 1, and the beam is marked as Point A. The instrument is then rotated 180 degrees to Wall 2, and the beam is marked as Point B. The instrument is then moved closer to Wall 2, leveled, and pointed at Wall 2 again, marking the beam as Point C. Finally, it's rotated 180 degrees back to Wall 1, marking the beam as Point D. The vertical distances between Points A and D, and Points B and C are measured. The instrument is within tolerance if the larger of these two differences is less than 1/4" at 25'. This method doubles the error, meaning a 1/4" difference at 25' indicates an actual accuracy of 1/8" at 25'.
The product comes with a two-year limited warranty. Users should register their product within 30 days of purchase at www.johnsonlevel.com/register. Non-warranty repairs and calibration must be performed by an authorized Johnson® service center. Users are advised not to attempt repairs or disassemble the tool, as this will void the warranty. Only original Johnson® parts and accessories should be used. For further assistance or troubleshooting, users can contact Johnson Level & Tool's Customer Service Department.
General| Brand | Johnson |
|---|---|
| Model | 40-6646 |
| Category | Laser Level |
| Language | English |
