Stanley Stud Sensor 300
The Stud Sensor 300 uses electronic signals to locate the center of studs, joists 
or live AC wires through drywall or other common building materials. Once 
the center of a stud has been detected in one pass across the surface, the 
Stud Sensor 300 gives a visual display and sounds an audible tone. A marking 
channel allows you to easily note the stud center and edges on the wall.
The Stud Sensor 300 will not detect objects in concrete, mortar, block or brick 
work, carpeting, foil faced materials, metallic surfaces or ceramic tiles. The 
Stud Sensor 300 is not designed to locate non-ferrous or plastic objects such 
as pipes.
Note: Read all instructions prior to operating the Stud Sensor 300 and DO NOT 
remove any labels from the tool.
WARNING:
Protect Your Eyes, Wear Safety Goggles.
Usage
Detecting Wood / Metal Studs
2
 Hold the Stud Sensor 300 fl at 
against the surface, making fi rm 
contact.
3
 Press in and hold the activation 
button. A series of tones will sound.
Note: The unit cannot be moved before 
calibration is complete.
6
 / 
7
 When it detects the stud 
center, the “Center” icon will appear on 
the LCD and an audible tone will sound. 
Use the marking channel located at the 
top of the unit to mark the stud center.
OPERATING INSTRUCTIONS
Battery 
1
 Open door on back of unit and connect a 9 volt battery 
(not included) to clip. Put battery back into case and close 
back battery door. 
Note: Recommend to replace a new 9 volt battery 
when low battery - “Low Battery” will appear on the 
LCD.
10
 If all segments of the LCD fl ash on and off when 
the activation button is pressed, move the Stud Sensor 
300 to a different location and try again. Releasing the 
activation button will turn off the sensor.
Note: While calibrating, the Stud Sensor 300 must not 
be placed directly over a stud, dense material such as 
metal, or over a wet or newly painted area, or it will not 
properly calibrate.
8
 Slide the Stud Sensor 300 slowly across the surface in a straight line. 
As it detects a stud, the unit will display the relative position of the stud 
on the screen.
•Marking Channel
•Live Wire Warning LED
•LCD Display
•Activation Button
•METAL SCAN Mode
•Stud Location Graphic
•Self-Calibration Complete
•Depth Detection Mode
4
 When the unit is calibrated the 
“Ready” icon will appear on the LCD.
5
 Keep holding the activation button 
during all of the following procedures.
Note: Once the Activation button is 
released, the unit shuts off.
•STUD or METAL / AC Mode Selection
•Live Wire Detected
•STUD Mode
•Low Battery Indicator
•AC TRACKING Mode