When it comes to automatic door sensors, there are two primary options that you can choose from: microwave sensors and infrared sensors. But what exactly is the difference between these two sensors? And which would make a better door sensor?
These two types of motion sensors are the most common ones you’ll find in commercial buildings, and it’s not hard to figure out why– both work efficiently at detecting moving people and objects, and immediately opening automatic doors.
To answer these questions, let us first break down how each one works.
The Infrared Sensor
The infrared sensor works by measuring the infrared light radiating from the objects in its field of view. All objects with a temperature above absolute zero emit heat energy in the form of radiation. This radiation cannot be seen by the human eye, but can be detected by electronic devices like the infrared sensor.
The infrared sensor conducts an analysis of a room or surrounding areas, and looks for a change in infrared energy. Should it detect a change, such as the presence of a moving person in the proximity, it will emit a pulse activating the automatic door sensors, which in turn prompts the doors to open.
Infrared sensors are also known as Passive Infrared Sensors. ‘Passive’ here refers to the fact that these sensors do not emit or generate energy for detection purposes; they work simply by detecting infrared radiation emitted or reflected from objects.
The Microwave Sensor
The microwave movement sensor works quite differently to the infrared sensor. It applies the Doppler effect in that it sends out microwave signals and measures the length of time it takes for these signals to bounce off of surrounding objects and return to it. This echo time is what it uses to calculate the distance of stationary objects around it. It first establishes a baseline room or area analysis to detect the current distance of all surrounding objects. When something comes into the detection area thereby interrupting the microwave signals and altering the echo time, it perceives this as a change in distance from the object and this sets off its trigger.
The microwave sensor works much like a RADAR or SONAR system, sending out signals to measure its distance from objects. But the microwave sensor can also detect motion through wood, plastic, glass and most other construction materials except metal. Metal acts as a shield, creating dead zones behind them. This can be both an advantage and disadvantage to the microwave sensor.
Now that we know what the difference is between the two, it’s time to answer the question: which is better? The answer however isn’t clear cut:
Comparison
So which sensor would be better for your automatic door? Generally, infrared sensors are more suitable for smaller, more compact entryways and well-controlled, indoor spaces, whereas microwave ones are good for large areas. But who says you need to choose anyway?
With Rotech’s selection of commercial automatic door sensors, you can get both infrared and microwave technology in one! We also have a great selection of microwave only and infrared only door sensors. Take a look at our product range today!
Sentinel Z58B flap barrier gates are typically used in areas where there is a need…
Whether security is your priority, or you need to monitor and manage the movement of…
Use Rotech's product comparison table to help choose the right PE safety beams to use…
Suitable for various applications including indoor or outdoor industrial settings, intersections, pedestrian crossings, construction zones,…
Our TriStar F21 full-height turnstile stands out for its extensive customisation capabilities. Compatiblilty with all…