52mm Glass Reed Switch – High-Sensitivity Magnetic Proximity Sensor for Security and Industrial Automation

Product Description The 52mm Glass Reed Switch is a high-sensitivity, hermetically sealed magnetic sensor designed for non-contact switching in security and industrial automation systems. This passive component consists of two flexible, ferromagnetic metal reeds enclosed in a protective glass envelope. In the presence of a magnetic field, the reeds are drawn together, completing the circuit. Because the contacts are sealed in an inert gas atmosphere, they are highly resistant to oxidation, corrosion, and sparking. It is the perfect choice for door and window alarm sensors, liquid level floats, and speed detection in environments where mechanical switches would fail due to dust or moisture.

Key Features

• Hermetically Sealed Design: Contacts are protected from external dust, humidity, and corrosion, ensuring an exceptionally long operational life.

• Non-Contact Activation: Triggers reliably using a permanent magnet or electromagnetic coil without physical friction or wear.

• Fast Switching Speed: Offers sub-millisecond response times, making it suitable for high-speed pulse counting and limit sensing.

• Passive Operation: Requires no standby power, making it ideal for battery-operated security nodes and ultra-low-power IoT devices.

• Compact Form Factor: The 52mm total length (with leads) allows for easy integration into custom enclosures and narrow structural gaps.

Technical Details

• Switching Logic: Normally Open (NO) configuration; the circuit remains open until a magnetic field is applied.

• Contact Material: Coated with high-grade Rhodium or Ruthenium for low contact resistance and superior wear characteristics.

• Dielectric Strength: Capable of withstanding up to 200V DC across open contacts, preventing accidental arcing.

• Inert Gas Filling: The glass tube is filled with Nitrogen to quench micro-arcs and prevent contact oxidation over millions of cycles.

• Mechanical Sensitivity: Highly responsive to low-strength magnetic fields; sensing distance depends on the strength of the external magnet used.

• Bounce Characteristics: Minimal contact bounce compared to traditional mechanical switches, essential for clean digital logic signals.

• Thermal Range: Operates consistently across a wide temperature spectrum from -40°C to +125°C.

• Vibration Resistance: The small mass of the internal reeds provides excellent stability against accidental triggers from mechanical vibration.

• Zero Standby Current: Since it is a physical contact switch, it draws 0.0µA when the circuit is inactive.

• Total Length: 52mm (approx.) including the flexible wire leads; the glass body measures approximately 14mm.

• Lead Versatility: The tin-plated leads can be easily bent or soldered onto PCBs, or connected to screw terminals.

• Inductive Load Protection: While rated for 0.5A, it is recommended to use a snubber circuit when switching inductive loads like relays.

• Life Expectancy: Rated for over 10 million operations under standard electrical loads.

• Logic Compatibility: Directly compatible with 3.3V, 5V, and 12V logic systems (Arduino, ESP32, PLC).

• Environment Grade: Ideal for explosive or hazardous environments as the switching spark is contained within the glass.