Johnson Level & Tool 40-6601 User Manual

©2021 Johnson Level & Tool - Rev. 2 11
7. Checking Accuracy
IMPORTANT: It is the responsibility of the user to verify
the calibration of the tool before each use.
Plumb Accuracy Check
Plumb accuracy can be
checked in two ways. The easier, though less
accurate method is to project the beam on a flat wall and use a
plumb bob to check the plumb of the beam.
The more accurate method to check the plumb line accuracy is to
follow these steps:
1. Place the tool on the floor in a fairly dark
room, approximately 10′
from a doorway.
2. Project the plumb beam through the
doorway.
3. Mark the plumb beam’s closet point to
the tool on the floor as Point 1.
4. Mark a spot 20′ away as Point 2.
5. Mark directly under the doorway as Point C.
6. Mark a spot directly above Point C, but on the doorway, as point D.
7. Move the tool to Point 2, and aim the plumb beam directly
through Point 1 and Point C.
8. Mark on the doorway Point E.
9. Measure the distance between Point D and Point E. If this
1
2
C
D
E
D
E
C
E
C
2
1
1
1
1
distance is < 1/8" for a 10' high doorway, then the tool is
properly calibrated.

Johnson Level & Tool 40-6601 Specifications

General

Brand	Johnson Level & Tool
Model	40-6601
Category	Measuring Instruments
Language	English