Door Sensor [How it Works, Types and Advantages]

Door Sensor [How it Works, Types and Advantages]

Worldwide, automatic doors are in use. You likely use them almost daily at supermarkets, schools, hospitals, and offices. Many buildings use automatically opening and closing doors as warm and welcoming entrances.

Automatic doors make life considerably simpler because they open when motion or touch is sensed or with the click of a button. In addition to being cozy, they also conserve energy.

Automatic doors use a variety of sensors, each with a specific function. Using sensors is the simplest method for detecting movement, pressure, or variations in infrared light without watching the door.

What is an automatic door?

Consider yourself in a grocery store. All the groceries you wanted are in your cart. You pay at the counter and take the bags of groceries with both hands after checking out. You proceed to the exit door. However, there is a minor issue. With both hands occupied, how are you supposed to open the door? Fortunately, the sliding glass doors appear to open by themselves for you to pass just as you approach the exit. What exactly happened, then? Was it a supernatural occurrence? No, pure science and technology are involved.

The main component of this technology is the sensor. Sensors sense the objects in their environment in the same way that their names suggest. Most automatic doors you see employ sensors mounted on the sides of the door to initiate door opening and closing.

All automatic gates have sensors that open and close the doors as needed. A variety of sensors can trigger an automatic door to open. Their use is determined by the particular specifications or door design.

Since the late 1950s, automatic doors for architectural purposes have become more common. These doors are now seen in many locations, including hospitals, airports, upscale shopping centers, office buildings, and hotels. Not only are automatic doors convenient for customers but also provide other benefits, including energy efficiency, security, and cleanliness.

History of automatic doors

Interestingly, a Greek mathematician by the name of Heron of Alexandria is to thank for the invention of the automatic doors we use daily. He was given credit for developing the first automated door system that we are familiar with today. However, his design used ropes and pulleys. His ingenious plan also involved pumping heated water into containers, which caused the doors to open.

Even though most of Heron of Alexandria's work has been destroyed, it prepared the path for the contemporary version we know today. Automatic doors were first made available for purchase in the 20th century. In reality, American engineers Horace H. Raymond and Sheldon S. Roby created the first optical system to activate automated doors in 1931. Following this, in 1954, Dee Horton and Lew Hewitt, another American couple, made automatic doors operated by mat actuators. These depended on an invisible electronic mechanism that opened automatically when it detected a person's weight.

In 1960, the first commercially viable automatic sliding doors hit the market, launching a brand-new business. Motion sensors for sliding doors were developed in the 1970s. The first doors with disabled access were built, and the concept of energy-efficient swinging doors was invented.

Infrared motion presence sensors were implemented for safety reasons in the 1980s, and motion sensor activation for sliding doors became the industry standard. In the 1990s, when the automated door market rose to prominence globally, the first automatic folding doors were developed.

Now, when it comes to modern automated door systems, most have sensors that assist in triggering the opening and closing of doors as needed.

The Crucial Role of Sensors in Automatic Doors

Automated doors wouldn't be automatic if sensors weren't used; instead, a button would be required to open them. The sensors are the technology that makes it possible for the doors to open and close without any physical effort on your part. When pressure or movement is detected, the doors will automatically open; when the sensor detects nothing, they will close.

Different types of sensors function in a variety of ways. Various sensors pick up the movement of someone approaching the doors. Some use infrared technology to identify when an image deviates from its regular settings, while others use pressure detection.

They are simple to install, dependable, and effective. To guarantee the job is done correctly and professionally, hiring a professional to install the sensors is crucial. They come in various designs to pick the ideal one for your doors and their intended use. They may also be well-hidden so as not to draw attention to themselves or detract from the overall appearance of your building.

How does an automatic door sensor work?

The automatic door opens after the door controller activates the gear motor to drive the belt and pulley after receiving an activation signal from the sensor. After a predetermined amount of time, the door begins to close if no one is seen inside the activation area.

Automatic door structure

An automatic door includes the following parts:

  • Door operator: A door operator opens and closes doors automatically using a series of driving and controlling mechanisms. It has features including a door controller and a gear motor.
  • Maintenance switch: During door maintenance, it is simple to turn on and off power to the door operator.
  • Activation sensor: Activation sensors deliver a signal to the door operator to activate the door's openings and closings.
  • Safety sensor: Activation sensors have difficulty detecting humans or items on the door track, while safety sensors, such as beam sensors, can.
  • Fanlight: Mounted between the header and the ceiling, made of glass or another material.
  • Transom: Inside the header, the box is where the door operator is mounted.
  • Sliding door panel: Materials, including tempered glass, aluminum, and stainless steel, are frequently used
  • Non-sliding door panel: Fixed door panel
  • Door lock

Automatic doors usages

Many buildings have automatic doors that allow for modern, barrier-free entrance, departure, and passage. They are especially well suited for structures with a lot of foot traffic. Today, they are regarded as practically standard in the following sectors:

  • Health/Hygiene: Automatic door systems are the hygienic means for guests, patients, doctors, and caregivers to pass through doorways in the healthcare industry. They can stop manually opening doors while also avoiding the transmission of germs from their hands.
  • Hotels and gastronomy: In many hotels, a distinguished and practical entryway serves as visitors' initial point of welcome. Automatic access to the kitchen and other rooms enables the workers to carry out their duties securely and guarantees efficient service. This industry's accessibility, safety, and hygiene are also significant advantages.
  • Retail sector: Automatic door systems direct customers into establishments and act as an elegant and welcoming entryway. They produce a cheery, welcoming atmosphere for shopping. They also contribute to energy conservation because they are only open when necessary, reducing the impact of outside heat and cold on the interior temperature.
  • Public buildings: The law now requires barrier-free access to public buildings. In this sector, automatic door systems provide a reliable and secure solution, especially in areas with heavy foot traffic.

What are Automatic Doors benefits?

Automatic doors are utilized in various busy locations, including hospitals, airports, shopping malls, office buildings, hotels, and other broad public and commercial structures. For those who use them, they deliver first-rate customer service. The three types of automatic doors are swing, slide, and rotating. There are many diverse applications for and advantages of automatic doors. Here are some of the primary applications and benefits of automatic doors:

Control movements

Since you can watch the doors opening every time, you can manage the flow of customers into your establishment. The number of times the doors open can be adjusted using various settings.

Weather circumstances

In windy weather, nobody will struggle to open the door because of the force of the wind, and the door only opens for a brief period, preventing the entry of chilly or rainy weather.


Everyone who uses automated doors enjoys its convenience, whether they are pushing strollers or wheelchairs, carrying bags in both hands, or, more frequently these days, holding a phone in one hand and a cup of coffee in the other. Visitors may enter your establishment quickly and effortlessly with an automatic door rather than waiting for a heavy door to open. Everyone should have access, regardless of their physical condition.

Enhanced security

Automatic doors can help with security management. Security will have the power to remotely operate the doors, allowing them to open them to specific traffic or shut them completely to keep individuals out. As an alternative, the doors can be configured to stay open, which is perfect in an emergency when the facility needs to be evacuated quickly.

Hygiene oversight

Automatic doors are an excellent option for places like hospitals and food plants where sanitation is crucial because they are hands-free. By boosting air pressure in the space, an automated door with an air-tight function can also stop dirt and dust from entering. An automatic door is a fantastic option for operating rooms and other regulated settings, like labs.

Saves space

Automatic doors are perfect for buildings where the lobby may be cramped. Employing a sliding or telescopic door may eliminate the additional floor space needed for a swing door.

Power Saving

The doors will only open as needed and close after the user, guaranteeing that they are mostly closed. This action is necessary to maintain the building's temperature and to save electricity.

The speed at which the door opens and closes is another aspect. The automatic door must be opened to access the services; the shorter the open time, the less energy is lost. Buildings whose doors are frequently left open require more energy to heat and cool. Revolving doors, on the other hand, are low-power systems that control the flow of people in and out and act as a natural barrier to maintaining the proper temperature. Never will the interior air come into close contact with the outer atmosphere.


Because they make it simple for everyone to enter, regardless of their age or physical capabilities, automatic doors offer exceptional customer service. Automatic doors for multipurpose restrooms are strongly advised in public facilities like stations and city offices in various countries, like Japan.

Simple to use and keep up

Automatic doors are made with high quality and safety requirements in mind, and they're also simple to use and maintain. Once installed, they require little maintenance, and issues are infrequent.

Professional appearance

Your entrance doors will be the first thing guests see; first impressions matter. Due to the low accessibility, manual doors leave a terrible first impression. Users perceive an automatic door better as they approach a building because of its elegance, convenience, security, and ease of use, which improves the brand's appearance.

Automatic doors can give a building a more professional appearance, drawing more people into your place of business.

What Types of Sensors Are Used in Automatic Doors?

Automated doors may have a wide range of sensors, and each type performs a particular function best suited to that sensor. The different kinds of sensors and how they operate are listed below:

Pressure Measuring

'Control mats' were employed as sensors in the 1960s to identify approaching pedestrians. These mats picked up the weight/pressure fluctuations on a particular patch of the ground in front of and behind the gates. If the weight in a specific area exceeded the predefined limit, the doors would open (lower than the typical human weight, the "trigger limit" was established).

Utilizing this type of technology can keep the doors open as long as there is pressure on the mat. In other words, they stay open if someone is walking or standing close to the doors. This sensor facilitates quick entry and leave and stops the doors from "closing in" on a person.

In modern automated door systems, pressure sensors are frequently used as secondary or backup. As a result, the pressure sensor is activated if the primary sensor malfunctions. Pressure sensors function by determining an object or person's weight. The automatic doors will open after receiving a signal from the sensors signaling the weight's pressure.

Photoelectric door sensor

Photoelectric door sensor is used in parking lot entrances or escalators. These sensors are based on through-beam type sensor system and trigger an alarm or send signal to controllers when the light beam is cut off. Through-beam or Thru-Beam have the following working principle:

  • To make or break a beam, two different devices are employed in thru-beam sensing, sometimes referred to as opposing mode. The light emitter is housed in one sensor, the receiver in the other. When an object blocks the light beam between two sensors, a thru-beam sensor picks it up. The most effective use of them in a filthy environment is through-beam sensors. It's crucial to remember that at least two independent parts will need to be installed for this gadget to function correctly.

Infrared sensor

These sophisticated sensors employ infrared technology to cause doors to open and close. When a person approaches the doors, the sensors recognize their heat signature and immediately open them because they detect variations in temperature in the region around them!

Passive infrared movement sensors are installed and store the infrared image they pick up within a predetermined range. Whenever the thermal image changes, the sensor produces a separate signal. These sensors are highly dependable when it comes to triggering an automatic gate to open. They can be tuned very precisely, have precise detection ranges, and are of a small design.

Active infrared sensors consist of a transmitter chip and at least two receiver chips. The high-performance optics in the receiver chips are present. The receiver can detect infrared light from the transmitter to determine whether an object or person is inside or outside the scanning zone. These sensors are ideal for use in swing, sliding, and rotating doors as protection against cutting or crushing edges.

Passive infrared movement sensors use infrared technology to capture images of their surroundings. The sensors will alert the automatic doors to open or close when the image changes, which a person or item would bring on.

Although these sensors function independently, they are frequently combined to prevent glitches or oversights inside a single system. If a person is moving too slowly or standing still close to the doors, pressure sensors can detect the person's weight and prevent the doors from closing until the weight is released, that is, until the person moves away from it or passes through the doorway. For instance, motion sensors trigger the opening mechanism as soon as they sense or "see" motion in front of the doors.

Radar Movement Sensor

These sensors are capable of locating people in a particular area. Because of this, radar movement sensors are appropriate for use as automatic gate openers. These sensors have the advantages of piercing foreign materials such as plaster, plastic, wood, etc., detecting objects and people, having changeable sensitivity levels, and determining the direction of movement. These sensors can sense when something or someone is close to the door and their direction of movement.

22nd Mar 2022 Saeed Abd

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