Summary of Sensor Types

Movement and presence

Multi-purpose technology is used for the combination of opening automatic doors and making them safe. These multi-purpose sensors also fulfil a large number of additional functions which can significantly increase the convenience of the door.

Advantages

• guarantees all-round safety for the user
• an activation and safety device

Radar movement sensors detect people in a fixed area. They are therefore ideal as opening activators for automatic doors.

Advantages

• penetrates foreign materials such as wood, plastic and plaster
• detects people and goods
• can be set to detect the direction of movement
• adjustable sensitivity

Disadvantages

• stationary objects are not detected
• sources of interference can cause malfunctions
• response sensitivity is dependent on the size, speed and angle of approach of the object
• imprecise detection range

After a short period of adjustment, passive infra-red movement sensors memorise the infra-red image they detect in the range for which they are configured. If this thermal image changes, the sensor creates a defined signal. Passive infra-red sensors are very reliable opening activators for automatic door systems.

Advantages

• very compact designs are possible
• can be set very accurately
• precise detection ranges

Disadvantages

• stationary objects are not detected
• goods without a temperature difference are not detected
• imprecise if the temperature difference between the object and the background is small

Active infra-red detectors consist of a transmitter and at least two receiver chips with high-performance optics. The receiver is able to recognise whether the infra-red light emitted from the transmitter is reflected by a person or object inside or outside the (background of) the scanning zone. In a modular construction system several beams can be allocated to lines or defined areas.

Active infra-red detectors are well suited for use as protection against crushing or cutting edges in revolving doors, sliding doors (replacements for protection leaves) and swing doors. The detectors can also be used as activation sensors for the door drive.

With background analysis

Advantages

• detection range can be set to 0 mm
• the transmitter can be tested
• detects reflective objects

Disadvantages

• background necessary
• dependent on the luminosity coefficient of the background

Without background analysis

Advantages

• no background necessary
• independent of the luminosity coefficient of the background

Disadvantages

• cannot detect persons/objects in very close proximity

Light beams are opto-electronic sensors which detect objects or persons by means of light. Light beams react to any interruption to the beam between the light transmitter and receiver. If an object is detected, the sensor creates a defined electric output signal.

Advantages

• reliable in use even in adverse ambient conditions
• very clearly defined trigger point
• few problems with reflective objects

Disadvantages

• cable to be installed in the door profile
• no surface protection