Types of infrared sensors detect people quality today

In today’s technological age, infrared sensors that detect people have become an essential part of life, from ensuring home security to optimizing production processes in industry. Understanding the function and application of this type of sensor not only helps businesses make the most of the benefits brought by technology, but also shapes the future of many industries. Let’s  learn more about the types of infrared sensor detects people with RX Tradex and its diverse applications in the article below.

1. What is a person detection infrared sensor?

A person detection infrared sensor is an infrared sensor device that uses infrared (IR) sensor technology to perceive human presence. This device works on the principle of detecting thermal radiation from the human body (whose temperature is about 37 degrees Celsius), as well as from animals or any object that emits infrared rays. 

When a person or object moves into the sensor’s detection area, changes in thermal radiation are recorded and processed, allowing the device to identify the presence and trigger corresponding responses such as turning on lights, alarms, or controlling other electronics.

2. Types of sensors that detect people

Currently, there are two common types of infrared sensors that detect people:

• Active infrared (IR) sensor: This sensor emits an infrared signal. When an object moves closer, the infrared signal will reflect back from the object and be detected by the sensor, thereby identifying the object’s presence.
• Passive infrared sensor (PIR): The sensor does not emit infrared rays, this sensor automatically detects and receives infrared radiation from objects that emit heat. When there are people or animals moving within the sensor range, a change in thermal radiation is detected and a signal is triggered.

Both types of sensors are widely used in security systems, automated lighting, and many other applications, thanks to their ability to accurately detect human presence and movement.

3. Pros and cons infrared sensor detects people

Infrared sensors that detect people offer many significant benefits in everyday life, however there are also some disadvantages to keep in mind when using. Here are the pros and cons of infrared sensors that detect people:

Advantage:

• Capable of detecting the movement and presence of people or animals with high sensitivity, even in low light or night conditions.
• Low energy consumption, especially passive sensors (PIR), extends battery life and reduces operating costs.
• Compact in design and easy to integrate into existing systems, infrared sensors are versatile and convenient to install and maintain.
• Widely used in many applications such as security systems, automatic lighting, electronic equipment control, and HVAC (heating, ventilation and air conditioning) systems.
• The operation is based on thermal radiation, so it is not affected by visible light, which makes it efficient to operate both during the day and at night.

Shortcoming:

• The detection range of infrared sensors may be limited, especially in large environments or when there are many obstructions
• The performance of the sensor can be affected by changes in ambient temperature, especially in high temperature conditions or when there are many other heat sources.
• It is not possible to detect movement or presence of people through obstructions such as walls, doors, or other solid objects.
• Other heat sources such as heaters, infrared lamps, or direct sunlight can cause interference and reduce sensor accuracy.

4. Motion or presence detection person sensor application

Sensors that detect people based on movement or presence are an important tool and are widely applied in many fields such as healthcare, manufacturing, transportation and in daily life. Some specific applications of this type of sensor can be mentioned as:

4.1. Application in security systems

• Intrusion alarms: Motion detection sensors are strategically installed in homes, offices, and public areas to detect the presence of intruders. When motion is detected, the system triggers an alarm.
• Surveillance cameras: Combined with security cameras, sensors help trigger motion recording, save memory and easily manage.

4.2. Integrating smart home system (smart home)

• Control electrical equipment: Activate electrical appliances such as fans, air conditioners, and sound systems when there are people in the room.
• Central control system: Integrated into smart home systems to optimize energy and improve utilities for users.

4.3. Application in industry

• Monitor and control production processes by detecting the presence and movement of personnel and machines.
• Monitor and control warehouse operations to enhance efficiency and minimize safety risks.

4.4. Health and Health Care

• Detects the patient’s movements in the hospital room, helps to monitor the state of health and prevent accidents.
• Activation of medical devices in the presence of patients or medical personnel.

4.5. Application in transportation

• Smart traffic light system: Adjust traffic light time based on traffic of people and vehicles.
• Parking system: Detects and guides vehicles into empty parking spaces, improving parking efficiency.

5. Advanced person sensor circuit

An advanced person sensor circuit is a type of infrared sensor circuit detects people using an infrared body temperature sensor to emit a beam beam with a high frequency of about 5kHz. This signal is picked up by an optical resistor in the receiver section. When no object cuts through the beam, the two parts of this circuit will be in phase, resulting in no output signal being generated. 

However, when an object moves and cuts through the infrared beam, the phase of the signal is skewed. This will be detected immediately by the optical resistor, which activates the 555 timer to give an alert through the speaker.

If there is no activity from the infrared sensor, the optical transistor will keep foot 2 of the 555 timer at a steady high, without producing any output signal. However, if any movement is detected, pin 2 of the timer will be set to low, triggering an alarm. The alarm time is adjusted through POT rheostat and C1 capacitor.

5.1. Active person detection sensor

Active person detection sensors typically consist of an LED to emit infrared light and a receiver to receive reflected signals from objects near the sensor. When an object appears within range of the sensor, it activates the LED and picks up the light reflected from that object. This application is often used in obstacle detection systems such as in mobile robots.

5.2. Passive Person Detection Sensor – Passive Infrared Sensor

Passive human sensors typically only receive and respond to infrared light from external sources such as people, animals, or heat sources. Instead of emitting light on its own, this sensor recognizes and converts signals from infrared light emitted by other objects. Therefore, it is called passive, only reactive and does not produce infrared radiation.

6. Summary

Infrared sensors detect people play an undeniable role in improving performance, safety, and utility in many sectors such as security, smart homes, and the manufacturing industry. Hopefully, this article has helped your business better understand the common types of infrared sensors that detect people today.

At the same time, to discover more advanced equipment and machinery in the field of manufacturing and supporting industries, you can participate in NEPCON Vietnam organized by RX Tradex. With the presence of hundreds of leading brands, the exhibition promises to be a great opportunity for you to access the latest technologies, apply in production and create breakthroughs in the production and business process of enterprises.