SN04-N Inductive Proximity Sensor – 4mm Detection Distance
The SN04-N Inductive Proximity Sensor is a non-contact metal detection switch designed for industrial automation, robotics, CNC machines, and position sensing applications.
Using high-frequency electromagnetic induction, the sensor detects nearby metallic objects without physical contact, providing reliable and repeatable switching performance.
Featuring a 4mm sensing distance, 10–30V DC operating voltage, and fast response frequency, the SN04-N is suitable for object detection, machine positioning, and automated control systems.
Key Features
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Non-Contact Metal Detection: Detects metallic objects without mechanical contact.
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4mm Sensing Distance: Suitable for short-range metal detection applications.
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NPN Output: Designed for connection to compatible industrial controllers and control circuits.
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10–30V DC Operation: Supports common industrial DC power supplies.
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Fast Response: Up to 500Hz switching frequency.
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High Repeatability: Provides consistent detection during repeated operations.
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Solid-State Switching: No mechanical contacts, reducing wear during operation.
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Resin-Sealed Housing: Designed for improved resistance to vibration, moisture, and industrial environments.
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Compact Rectangular Design: Convenient for installation on machinery and automation equipment.
Technical Specifications
| Parameter |
Specification |
| Model |
SN04-N |
| Sensor Type |
Inductive Proximity Sensor |
| Detection Method |
Electromagnetic Induction |
| Detectable Material |
Metal |
| Sensing Distance |
4mm |
| Operating Voltage |
10–30V DC |
| Output Type |
NPN |
| Output Configuration |
Normally Open (verify model marking) |
| Rated Output Current |
400mA (supplier specification) |
| Response Frequency |
500Hz |
| Connection |
3-Wire Cable |
| Housing Color |
Blue / Black |
| Housing Type |
Rectangular |
| Mounting |
Screw Mounting |
| Contact Type |
Non-Contact |
| Applications |
Industrial Automation / Metal Detection |
Pin Configuration & Wiring
Typical 3-wire SN04-N sensor connections:
| Wire Color |
Function |
Connection |
| Brown |
V+ |
+10–30V DC |
| Blue |
GND |
Power Supply Ground |
| Black |
Output |
NPN Switching Signal |
Working Principle
When a metallic object enters the sensor's detection range, the internal oscillator detects the change in electromagnetic conditions and activates the output.
For a typical NPN normally open sensor:
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Metal Detected: Output transistor switches ON and pulls the output toward ground.
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No Metal Detected: Output transistor remains OFF.
Applications
- CNC Machine Homing
- 3D Printer Position Detection
- Industrial Automation Systems
- Conveyor Belt Object Detection
- Metal Presence Detection
- Robotic Position Sensing
- Machine Limit Detection
- Automated Production Equipment
- PLC Input Switching
Compatibility
The SN04-N can be integrated with:
- Arduino Boards
- ESP32 Microcontrollers
- Raspberry Pi
- PLC Controllers
- Industrial Control Systems
Important: The sensor operates from 10–30V DC. Arduino, ESP32, and Raspberry Pi GPIO pins must not be connected directly to an output that can exceed their input voltage ratings. Use a suitable pull-up, interface circuit, optocoupler, or level-shifting arrangement as required.
Important Notes
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Metal Detection Only: Does not detect ordinary plastic, wood, or glass.
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Sensing Distance: The specified 4mm distance is typically based on a standard metal target; actual detection distance varies with metal type and target size.
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Output Configuration: Confirm the NPN normally open configuration from the product label before wiring.
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Power Supply: Requires 10–30V DC.
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Load Current: Do not exceed the verified output current rating.
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Water Resistance: The resin-sealed construction offers environmental protection, but no specific IP rating is confirmed.
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Electrical Safety: Disconnect power before wiring or adjusting the sensor.
Package Includes
