A Brief Analysis of Major Types of Industrial Safety Sensors

The core objective of industrial safety sensors is not only "sensing" and "alarming," but also to achieve "safety control"—directly and reliably linking with machine control systems to trigger safe stops or enter safe states. Industrial safety sensors are diverse, and based on their functions and application scenarios, they can be mainly divided into the following categories for reference:

1. Area Protection and Entry Detection

Used to establish invisible safety barriers in hazardous areas (such as robot workstations, stamping machines, and assembly lines).

1.1  Safety Light Curtain/Grate: Forms one or more rows of invisible infrared light beams at the entrance to a hazardous area. When a person or object interrupts any beam, the sensor immediately sends a safety stop signal to the machine control system. It is a modern solution to replace traditional physical protective barriers.

1.2  Safety Laser Scanner: Performs a two-dimensional scan of the surrounding environment using a rotating laser beam, constructing a planar map. Warning zones and stop zones can be set. When an object enters the warning zone, it triggers an audible and visual alarm; entering the stop zone immediately stops the machine. Commonly used for perimeter protection of AGVs and large machinery.

1.3  Safety Mat/Safety Carpet: When a person steps on the mat laid around a hazardous area, its internal contacts close, triggering a stop signal. Suitable for fixed entrance areas.

1.4  Safety Door Lock/Interlock Device: Installed on protective doors or covers. Machine operation is only permitted when the door is fully closed and locked. Power is immediately cut off or the machine stops once the door is opened. Available in coded and non-coded versions; coded versions prevent bypassing with simple tools.

2. Position and Presence Detection

Used to ensure machine parts are in the correct, safe position, or to detect the presence of personnel/objects in a specific area.

2.1  Safety Limit Switch: Reinforced proximity or mechanical switches used to detect the position of protective doors, the start/end point of a robot arm, etc. Features high reliability, impact resistance, and long lifespan.

2.2  Safety Magnetic Switch: Similar to industrial door interlocks, but uses a non-contact magnetic principle.

2.3  Safety Proximity Sensor: Detects the presence of metallic or non-metallic objects non-contactly using principles such as inductance and capacitance. Commonly used to detect whether a workpiece is in position, whether a hand is in a hazardous area, etc.

3. Emergency Stop and Manual Control

Used for manual intervention in emergency situations.

3.1  Emergency Stop Button: A large, prominent red button with a self-locking function (remains activated after being pressed and requires rotation or pulling to reset). Pressing it directly cuts off the safety circuit, stopping the equipment in the fastest and safest way.

3.2  Safety Pull-Rope Switch: An emergency stop device installed along the conveyor belt or production line; pulling the wire rope at any position triggers a stop.

4. Motion Control and Speed Monitoring

Used to monitor the motion status of rotating equipment to prevent accidental starts or overspeeding.

4.1  Safety Speed Monitor: Monitors the motor's speed; when the speed is below or above a set safety threshold (e.g., when the equipment needs to crawl at low speed during maintenance), it triggers the corresponding action.

4.2  Safety Encoder: Used to accurately measure the position and speed of shafts and provide reliable position feedback to the safety control system; commonly used in robots and servo drive systems.

5. Environmental and Condition Monitoring

Monitoring industrial environmental parameters that may cause safety accidents.

5.1  Safety Temperature Sensors: Monitor overheating of motors, bearings, or reactors to prevent fires or equipment malfunctions.

5.2  Flame and Gas Detectors: Detect flammable gas leaks or initial flames in high-risk environments such as chemical and petroleum industries.

5.3  Pressure Safety Sensors: Monitor pressure in pipelines or containers to prevent overpressure explosions.

Industrial safety sensors are specifically designed for industrial environments to prevent personal injury, equipment damage, and production interruptions by detecting hazardous conditions, personnel locations, or equipment anomalies. For more information/advice on safety sensors or to purchase other high-quality hydraulic presses, please contact us (or scan the WhatsApp QR code below). Jianlong Hydraulic Technology will provide you with personalized and customized professional solutions and is dedicated to serving you.