Johnson JRT300-RDHV-S User manual

©2023 Johnson Level & Tool 1
4000' Dual Slope Rotary Laser
Model No. JRT300-RDHV-S
Model No. JRT300-RDHV-K
Instruction Manual
Congratulations on your choice of this 4000' Dual Slope Rotary
Laser Level. We suggest you read this instruction manual thoroughly
before using the instrument. Save this instruction manual for future
use.
This is a Class 3R laser tool and is manufactured to comply with
CRF21, parts 1040.10 and 1040.11 as well as international safety rule
IEC285.

2 ©2023 Johnson Level & Tool
Table of Contents
1. Kit Contents
2. Safety Instructions
3. Getting Started
4. Warning Labels
5. Parts/Components
6. Operation Instructions
7. Accuracy Check
8. Specifications
9. Care and Handling
10. Product Warranty &
Registration
11. Accessories
12. Trouble Shooting
1. Kit Contents
Description for Model JRT300-RDHV-S Qty.
4000' Dual Slope Rotary Laser 1
Alkaline Battery Compartment (batteries not included) 2
Lithium-ion Batteries 2
Detector with Clamp and 2 “AAA” Alkaline Batteries 1
Remote with 2 “AAA” Alkaline Batteries 1
Magnetic Target 1
Type C, USB adapter/charger 1
8' Grade Rod 1
Tripod 1
Hard-Shell Carrying Case 1
Description for Model JRT300-RDHV-K Qty.
4000' Dual Slope Rotary Laser 1
Alkaline Battery Compartment (batteries not included) 2
Lithium-ion Batteries 2
Detector with Clamp and 2 “AAA” Alkaline Batteries 1
Remote with 2 “AAA” Alkaline Batteries 1
Magnetic Target 1
Type C, USB adapter/charger 1
Hard-Shell Carrying Case 1

©2023 Johnson Level & Tool 3
2. Safety Instructions
CAUTION!
Class 3R Laser Product
Max. Power Output: ≤5mW
Wavelength: 630-650nm
THIS TOOL EMITS LASER RADIATION.
DO NOT STARE INTO BEAM.
AVOID DIRECT EYE EXPOSURE.
ATTENTION IMPORTANT
• Read all instructions prior to operating this laser tool. Do not remove
any labels from tool.
• Do not stare directly at the laser beam.
• Do not project the laser beam directly into the eyes of others.
• Do not set up laser tool at eye level or operate the tool near a reflective
surface as the laser beam could be projected into your eyes or into the
eyes of others.
• Do not place the laser tool in a manner that may cause someone to
unintentionally look into the laser beam. Serious eye injury may result.
• Do not operate the tool in explosive environments, i.e. in the presence
of gases or flammable liquids.
• Keep the laser tool out of the reach of children and other untrained
persons.
• Do not attempt to view the laser beam through optical tools such as
telescopes as serious eye injury may result.
• Always turn the laser tool off when not in use or left unattended for a
period of time.

4 ©2023 Johnson Level & Tool
3. Getting Started
IMPORTANT: It is the responsibility of the user to verify the
calibration of the instrument before each use. See section 7.
How to Charge Lithium-ion Batteries
The rotary laser unit is shipped with two Lithium-ion (Li-ion)
batteries installed but not charged. Li-ion batteries can be charged
either installed or external to the unit. Follow the steps below to
charge the batteries.
How to Charge Lithium-ion Batteries Inside the Unit
1. Slide open the battery recharge
port on the front of the rotary laser.
(Figure 1)
RL-RHV
RPMRPM
X
Y
X
X
Y
MAN
Figure 1
2. Connect the Type C, USB adapter/
charger to the rotary laser recharge
port. (Figure 2)
3. Connect the opposite end of charging
cable to a power source and note
that a green light next to the charging
port lights up. Charge time is typically
5 hours.
4. When charged using this method,
the battery charge is indicated by
LED light "b". See Operating Panel
Overview.
Green = ≥30%
Red = 10% ≤≥30%
Flashing Red = ≤10%
RL-RHV
RPMRPM
X
Y
X
X
Y
MAN
Figure 2

©2023 Johnson Level & Tool 5
5. Disconnect the Type C, USB adapter/
charger and close the recharge port.
(Figure 3)
RL-RHV
RPMRPM
X
Y
X
X
Y
MAN
Figure 3
How to Charge Lithium-ion Batteries Outside the Unit
1. Push in and turn the battery lock
knob clockwise to the “Unlock”
position. (Figure 4)
Figure 4
2. Remove battery compartment from
rotary laser. (Figure 5)
3. Remove each battery case from the
battery compartment.
Figure 5

6 ©2023 Johnson Level & Tool
4. Check the fuel gauge status
of the Li-ion battery. Press the
micro switch on the battery.
Note which LEDs light up. See
the table below to determine
the power status of the battery.
The LEDs will turn off after
three seconds. (Figure 6)
LED1
LED2
LED3
Micro
Switch
Figure 6
Fuel Gauge LED1 LED2 LED3
Volt of battery < 3.5V ON OFF OFF
3.5V ≤Volt of battery <3.8V ON ON OFF
3.8V ≤Volt of battery ON ON ON
5. Connect the Type C, USB adapter/
charger to battery charging port
located on the front of the battery.
(Figure 7)
6. Connect the opposite end of charging
cable to a power source and note
that battery charging LEDs light up.
When all three are lit, the battery is
fully charged. Charge time is typically
5 hours. See the table below to
determine the charging status of the
battery.
Figure 7
Fuel Gauge LED1 LED2 LED3
Volt of battery < 3.6V Flashing OFF OFF
3.6V ≤Volt of battery <3.9V ON Flashing OFF
3.9V ≤Volt of battery ON ON Flashing
4.165V ≤Volt of battery <4.235
(fully charged)
ON ON ON

©2023 Johnson Level & Tool 7
7. Reinsert the battery cases into the
battery compartment. Be sure the end
with the openings is aligned with the
opening on the rear of the battery
compartment. (Figure 8)
Figure 8
8. Reinsert the battery compartment into
the rotary laser. (Figure 9)
Figure 9
9. Push in and turn the battery lock knob
counterclockwise to the “Lock”
position to lock the battery cover.
(Figure 10)
Figure 10
How to Install or Replace Alkaline Batteries
NOTE: Always check that the battery compartment lock knob is in
the “Unlock” position before removing and/or replacing batteries.
1. Push in and turn the battery lock
knob clockwise to the “Unlock”
position. (Figure 11)
Figure 11

8 ©2023 Johnson Level & Tool
2. Remove battery compartment from
rotary laser. (Figure 12)
3. Remove each battery case from the
battery compartment.
Figure 12
4. Slide the covers off the battery
cases and insert three “AA” alkaline
batteries into each case according
to the polarity illustrated inside.
(Figure 13)
Figure 13
5. Reinstall the covers and reinsert
the battery cases into the battery
compartment. Be sure the end with
the openings is aligned with the
opening on the rear of the battery
compartment. (Figure 14)
Figure 14
6. Reinsert the battery compartment into
the rotary laser. (Figure 15)
Figure 15

©2023 Johnson Level & Tool 9
7. Push in and turn the battery lock knob
counterclockwise to the “Lock”
position to lock the battery cover.
(Figure 16)
Figure 16
How to Use the Type C, USB adapter/charger
If no batteries (Lithium-ion or alkaline) are available, you can
connect a Type C, USB adapter/charger power cord or power bank
to the rotary laser using the battery recharge port, and connect the
opposite end of charging cable to a power source.

10 ©2023 Johnson Level & Tool
Operating Panel Overview
RL-RHV
RPMRPM
X
Y
XX
Y
MAN
4
6
a
2
3
5
c
d
e
7f
g
1b
Push Buttons
1. ON/OFF button
2. Rotation Speed Selection button
(600rpm-1200rpm-0-100rpm-300rpm)
3. Line Operation and Length Operation button (15°, 30°, 60°, 0°)
4. Shock Warning Indicator button
5. Dual-Axis Slope Operation button
6. Upper/Clockwise Direction button
7. Lower/Counterclockwise Direction button