User Manual

Accuracy Calibration

• Set the grade at +0.01 - +0.02%.

• Turn off the unit.

• Press and hold “left arrow” and “right arrow” keys.

• Press and release “power on/off” key when holding the “left arrow” and “right

arrow” keys.

• Hold the “left arrow” and “right arrow” keys until “mem clear” shows on the screen.

• Recalibrate the laser until |(A2-A1) - (B2-B1)| is equal or less than 3mm.

• When |(A2-A1)-(B2-B1)| is greater than 6mm, you need to contact a Johnson

authorized repair center.

9. Technical Specifications

Laser Wavelength 635nm±10

Laser Classification Class IIIa

Maximum Power Output ≤5mW

Grade Range -20% to +40%

Grade Display 00.001%

Accuracy ±1/16” at 100’ (±5mm at 100m; ±10 arc sec)

Self-Leveling Range ± 5°

Left and Right Scan ± 4°

Power Supply 4 “D” alkaline batteries, rechargeable

Ni-MH battery pack, 12V adapter, car adapter

Battery Life Ni-MH: Approximately 64 hours continuous use

Alkaline: Approximately 40 hours continuous use

Dimensions 5.19” x 14.96”

(132 x 380mm)

Weight 13.2 lbs. (6 Kg)

Working Temperature -4°F to 122°F (-20°C to +50°C)

IP Protection Class 68 nitrogen purged