I was wondering if you could help me with understanding how an infrared detector works. It is just a cheap one that comes with an emitter from Radioshack. I can't find any websites that tell me what I want to know. What makes the detector detect infrared? I just don't get it.
Certainly, I can help you with understanding how an infrared detector works!
An infrared detector, also known as an infrared sensor or an IR detector, is a device that is designed to detect and measure infrared radiation. It detects infrared radiation using a material that is sensitive to this type of electromagnetic radiation.
Infrared radiation is a form of light that has longer wavelengths than visible light. It falls in the electromagnetic spectrum between visible light and microwaves. Infrared radiation is commonly emitted by warm objects and is invisible to the human eye, which is why it is often used for applications such as night vision, temperature measurement, and remote controls.
Now, let's talk about how the infrared detector detects this type of radiation. The basic principle behind an infrared detector is that when it is exposed to infrared radiation, it generates an electrical signal.
Inexpensive infrared detectors, like the one you mentioned, often use a technology called photoconductive detection. These detectors consist of a material that changes its electrical conductivity in response to infrared radiation. The most commonly used material for this purpose is a substance called lead sulfide (PbS).
Here's how it works:
1. When infrared radiation reaches the detector, it interacts with the material. The photons (particles of light) transfer energy to the atoms in the material.
2. This energy causes some of the atoms to become excited, promoting electrons from their original energy level to higher energy levels within the material.
3. As a result, the electrical conductivity of the material increases because the excited electrons are now free to move and carry an electrical charge.
4. The change in electrical conductivity is then converted into an electrical signal, which can be amplified and processed by electronic circuitry.
Inexpensive infrared detectors typically require an external source of infrared radiation, such as the emitter that comes with the detector kit you mentioned. The emitter emits infrared radiation, which is then detected by the infrared detector.
It's worth noting that there are different types of infrared detectors, including thermal detectors and photovoltaic detectors, which operate on different principles. However, for a basic understanding of how an inexpensive infrared detector works, the photoconductive detection principle using lead sulfide is the most common.
I hope this explanation helps you understand how an infrared detector works!