Description
LJ12A3-4-Z/BY Inductive Proximity Sensor NPN NO 4mm DC 6-36V – Reliable Industrial Metal Detector
📚 Table of Contents
🔍 Overview
The LJ12A3-4-Z/BY Inductive Proximity Sensor NPN NO 4mm DC 6-36V is a reliable and widely used industrial sensor ideal for non-contact metal object detection. Whether you’re building an automation project, an industrial control panel, or a DIY machine, this sensor offers precision, speed, and durability.
⚙️ Key Features
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Model: LJ12A3-4-Z/BY
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Type: Inductive Proximity Sensor
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Output Type: NPN Normally Open (NO)
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Detection Distance: 4mm ±10%
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Voltage: DC 6–36V
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Current: Up to 300mA
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Material: Durable aluminum shell
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Wiring: 3-wire (Brown, Blue, Black)
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Detects: Iron and other ferrous metals
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Thread Size: M12 x 42mm
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Cable Length: 1M (3.3 feet)
📐 Technical Specifications
| Specification | Value |
|---|---|
| Detection Distance | 4mm ±10% |
| Voltage Supply | 6V to 36V DC |
| Current Load | Max 300mA |
| Output Type | NPN, Normally Open |
| Diameter | 12mm |
| Shell Material | Aluminum alloy |
| Wire Type | 3-Wire |
| Detectable Object | Ferrous Metal (Iron) |
| Cable Length | 1 Meter |
💡 Why Choose LJ12A3-4-Z/BY Sensor?
The LJ12A3-4-Z/BY Inductive Proximity Sensor NPN NO 4mm DC 6-36V stands out due to its precise detection, affordability, and ease of installation. It is perfect for any industrial or academic project that requires reliable metal detection. The robust aluminum shell offers protection in harsh environments.
Some advantages include:
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No physical contact required
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High switching frequency
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Maintenance-free operation
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Immune to dirt and moisture
🧰 Applications
This sensor is used in various industries and fields, such as:
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Automated machinery
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Conveyor belt systems
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CNC machines
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3D Printers
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Object counting systems
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Position detection
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DIY robotics projects
🔌 Wiring & Installation
The wiring is simple and follows the NPN configuration:
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Brown: +V (6V–36V DC)
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Blue: GND
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Black: Signal (NO output)
📌 Mount the sensor using the two included nuts. Adjust the detection distance with precision based on your application need.
🛒 Buy from HTEBD
You can purchase this high-quality LJ12A3-4-Z/BY Inductive Proximity Sensor NPN NO 4mm DC 6-36V right now from:
🔗 HTEBD Online Store
🔗 Facebook Page for support and offers
We ensure:
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Fast delivery all over Bangladesh
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Affordable price
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Genuine quality products
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Excellent customer support

❓ FAQs
Q1: What is the difference between PNP and NPN sensors?
A: PNP sensors source current to the load, whereas NPN sensors sink current from the load. NPN is generally used where the control system requires positive logic.
Q2: Can it detect non-metallic objects?
A: No, inductive sensors like LJ12A3-4-Z/BY are specifically for detecting ferrous metals like iron.
Q3: Is it waterproof?
A: The sensor has some moisture resistance due to its aluminum casing, but it’s not fully waterproof. Use with protective housing if needed.
✅ Conclusion
The LJ12A3-4-Z/BY Inductive Proximity Sensor NPN NO 4mm DC 6-36V is an affordable, accurate, and durable solution for your automation needs. With easy integration, consistent performance, and versatile use cases, it is a go-to sensor for makers and professionals alike.
🛍️ Don’t wait! Get yours now at HTEBD Online Store and improve the intelligence of your next project.







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