With the advent of thermal imaging cameras, it is now possible to see inside a house or building without opening the door or window. But “Does glass block thermal imaging?” Many people believe that thermal imaging cameras cannot see through glass. Let’s explore the facts.
Thermal imaging is the practice of using infrared radiation (IR) to observe an object or person by determining its temperature. This can be used to detect what is happening within a room or on a human body. It allows doctors to see heat signatures under the skin, which can indicate problems with certain organs or diseases. This technology is also used in crime detection, security, law enforcement and even used in Infrared Camera For Roof Inspection.
Initially, this technology was very expensive and only used by the military. But now, thermal imaging is becoming more affordable and more popular. Now you can get the best Thermal Camera for Under $500 and if you have a bit more budget, you can even buy the Best thermal monocular under 1000. How cool is it?
But the most important thing is that the user must know what is thermal imaging and to which extent this technology can see through things like glass, metal, concrete, etc.
Does Glass Block Thermal Imaging?
In short, yes. Thermal imaging technology works by detecting differences in infrared wavelengths between materials. Glass and many windows and polished materials are acts like mirrors to infrared light, they reflect the infrared light back and you will not be able to see the other side of the glass.
Why can’t Thermal Imaging pass through Glass?
Thermal imaging technology is based on detecting infrared radiations.
The term “infrared” refers to any wave that has a longer wavelength than that of visible light. Infrared waves are invisible to the human eye. They can be detected by special devices called “thermometers”. A thermometer detects the amount of infrared radiation and displays it on the screen. For example, if you were to place your hand over an infrared thermometer, the device would detect the heat that your hand is emitting. The thermometer measures this radiation and displays the temperature of your hand on its screen.
The human body and animals generate heat and so also generate infrared radiations. These radiations are the strongest having a wavelength of 9.4μm. The infrared radiations having this range can’t pass through many materials like glass, ordinary windows, and plastic. However, visible light can pass through these materials.
Many materials that are opaque to visible light can pass IR radiations like silicon and germanium. That’s why IR can pass through windows made up of silicon and see what is on the other side of the window. Do you know Aluminum Foil also Block Thermal Imaging?
What is Glass? Why it can’t pass thermal imaging through?
What is Glass?
Glass is a non-metallic material that is formed by fusing sand with lime and soda. It is often transparent or translucent, but it can also be colored. Glass is generally used in windows, mirrors, and other optical components.
Thermal Imaging Test on Glass
In order to accurately test thermal imaging on glass, we used a digital camera and a thermal imaging camera. We then compared the results and saw that the images were not similar.
The thermal camera could not see through the glass, as glass is a highly reflective material and infrared radiation when colliding with glass, reflected back. The resulting image was actually the reflective temperature of the objects. For example, if you are taking an image from a thermal camera by standing in front of the window, the resulting image was your own body temperature reflected back from the glass.
The digital camera, on the other hand, could see through the glass as visible light can pass through the glass and be able to capture the image of the other side.
Why Glass is transparent to visible light?
When visible light hit the glass surface, the waves of visible light do not have enough energy to excite the electrons thus pass through the glass and you can see what’s on the other side.
But when infrared radiation transmits through glass, waves do not have enough energy to excite the electrons within, thus blocking the radiation and reflecting it back.
Frequently Asked Questions
Can infrared light pass through glass?
Infrared light is a form of electromagnetic wave. It has a longer wavelength than that of visible light so the human eye can’t see infrared radiations.
Which radiations can pass through the material, depends upon the arrangement of electrons in that particular material and the wavelength of the light hitting it.
Different wavelengths of light contain different amounts of energy. When infrared light hit the glass, most of the energy is absorbed by the electrons in the glass, so it can’t pass through the glass, however, certain wavelengths of infrared light can pass as their photons are not absorbed by the glass just like visible light.
Can thermal imaging see-through metal?
No, thermal imaging can’t see through metal. However, highly conductive metals can show cold spots and hot spots, and even things inside the metal container. For details please read, Can Thermal Imaging See-Through Metal?
Can You See Infrared Cameras At Night?
When some infrared rays chase you, you can,t see them, however, if you think someone is spying on you, you can use your phone camera to see infrared cameras at night.
Does Aluminum Foil Block Thermal Imaging?
Yes, aluminum foil blocks thermal imaging. If you cover something with aluminum foil, it reduces the overall sensitivity of the object and contains its heat inside. As the thermal camera detects things through heat signals, it can’t catch heat signals and the object remained unnoticed.
Thermal imaging is an effective way to detect people and things. However, the user should be aware of the limitations of the technology. The user must know what to expect and what not to expect when using this type of equipment. For example, thermal imaging can’t see through glass, metal, thick walls, concrete, and aluminum foil. In fact, thermal imaging can only detect heat signals with the help of infrared light. If IR light is opaque to the material, you can’t see through that material.
Related Post: How To Block Infrared Thermal Imaging?
My name is Sana and I’m one of the senior authors at SmartHomeFlix. I have a master’s degree in computer science that I no longer have any use of. My passion is writing articles on technology, speakers in particular which is also my on the site. Former JBL employee.