Johnson Level & Tool Mfg. 40-6936 User Manual

Page 30

• Position the telescope to zero after power-on. Tighten the vertical

clamp and the instrument will display the current value in the
upright position.

• Slowly turn the foot screw in one direction about 1/2” or so (circle

distance), the value of upright angle changes correspondingly until
it disappears and the symbol “b” is shown, this means the incline
of the instrument’s axis has exceeded the compensation range.

When turning the foot screw in reverse, the instrument goes back

to display the upright angle (repeat testing and observe the
changes on the critical point), this means the compensation device
is working.

Calibrating
When the compensation doesn’t work well or works abnormally, send
the instrument to an authorized repair facility for repairs.

Vertical Plate Angle Specification ( “i” angle) and its Zero Setting

• After mounting and leveling, power on the instrument. Aim the tele

scope at any clear target A to get the reading L, which is the
upright angle plate left reading.

• Turn the telescope to the reverse position and aim at target A again

to get the reading R, which is the upright angle plate right reading.

• If upright angle is in the zenith angle mode, then i=(L+R-360°) /2.

If upright angle is in the vertical angle mode, then i=(L+R-180°)/2
or i=(L+R-540°)/2

• If the specification errors |i|° ≤ 10”, 0 reset of the upright plate

specification is necessary.

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