What is the purpose of infrared sensors?
4 Answers
Here are the uses of infrared sensors: 1. Perceive certain characteristics of the surrounding environment; 2. Measure the heat emitted by objects and detect motion: For example, cars and televisions use infrared detectors to interpret signals sent from remote controls. Below is the classification of infrared sensors based on operation: 1. Thermal type: Converts part of infrared rays into heat, extracting output signals such as resistance changes and electromotive force through heat. 2. Quantum type: Utilizes the photoelectric effect of semiconductor migration to absorb energy differences and the quantum type that employs the photovoltaic effect of PN junctions.
The infrared sensors installed in cars are incredibly useful! The most practical feature is night vision, especially when driving on mountain roads at night, allowing you to detect pedestrians or animals from over a hundred meters away. For example, high-end BMW models use cameras that capture temperature changes, marking heat-emitting objects in yellow on the dashboard. Additionally, collision avoidance systems also use infrared distance measurement, with front sensors scanning the road 24/7. Last time I drove long-distance in heavy fog, regular headlights couldn't penetrate the mist at all, so I relied entirely on infrared imaging to see roadside barriers clearly. Some new energy vehicles even use it to monitor battery temperature, with high-temperature warnings helping prevent fires. Usually, parking sensors give false alarms for shadows from trees, but switching to infrared probes makes them much more accurate.
The most commonly seen are probably induction lights, right? The ones that automatically turn on when you approach a supermarket door use passive infrared sensors. My digital thermometer at home also works on the infrared principle, allowing temperature measurement without touching the forehead. Factories rely on this even more—equipment overheating triggers alarms to prevent accidents, and conveyor belts stop immediately if materials get stuck. During the pandemic, those rapid temperature screening gates at subway stations could scan five or six people per second. Fire alarms detect smoke particles via infrared, which is three times faster than traditional smoke detectors. Recently, even smartphones have started incorporating infrared distance measurement to prevent photos from impersonating faces during unlocking or payment.
It's most widely used in warehouse management. The infrared scanner on a barcode gun automatically records inventory into the system by scanning shelves. Sensors on logistics sorting belts can identify package sizes for categorization. Agricultural drones equipped with infrared cameras can determine which crops need water after a single flyover. Smart homes also rely heavily on it—air conditioners detect human positions for directional airflow, and surveillance cameras use infrared imaging at night. For power inspections, portable devices can detect transformer overheating from a distance.
