by Rosaele Tremblay
Hello, I am a high school student writing a paper for my science project and I would like any feedback from the InfraMation readers (scientists or thermographers to see if I am on track with this idea or if anyone has suggestions as to how we can make this work. Thank you for any input.
You can provide comments and suggestions for Rosaele by leaving a comment on this post - Editor
Introduction
The electromagnetic spectrum includes gamma rays, X-rays, ultraviolet, visible, infrared, microwaves, and radio waves and each of them has a different wavelength and frequency. Infrared radiation is between visible light and the microwave portions of the electromagnetic spectrum and it is not visible to the human eye. Some animals do exist which see in infrared such as a few different snakes. Three categories exist in infrared: near, mid and far-infrared. Near-infrared is the closest to visible light and far-infrared is closer to the microwave portions. Infrared radiations are all around us every day coming from sunlight, a fire, radiator, a warm sidewalk and the TV remote. Everything on earth gives off heat when molecules begin to move and the higher the temperature of an object, the more the atoms and molecules will be moving which will produce a greater amount of infrared radiation. Objects with a temperature above absolute 0 radiate in infrared including the objects we perceive to be cold or freezing such as ice cubes or objects which are hot but do not visibly appear to be hot emit heat.
These shots of a coffee mug are in three different palettes to show that we assign the colors to gray steps. Human eyes see ten gray steps so to see the colors in definition we can assign 10 colors to them like in these shots. In these, white is hot and black is cool, but we can also invert these so that white is cool and black is hot, this is up to the thermographer.
The real Infrared, note not the colors but the reflection in the foreground which is the heat that is being emitted from the cup and reflected into the camera lens, some of that heat is being absorbed into the table and some of that heat is being transferred through the table and the camera is seeing the radiation portion off the table. This is due to emissivity and is called T reflection.
Black Ice
Black ice is like a glaze that forms on surfaces in the winter such as roads, sidewalks and driveways. It forms around freezing point and happens usually because of a light freezing rain, due to the melting and re-freezing of snow, water or ice on certain surfaces or sometimes it is even due to the heat of the tires on the road which quickly then cools and freezes again. Usually it forms at night or early in the morning when the temperature are low and the sun is not yet present. The air and surface temp of the road could be significantly different by at least 20 degrees F but when the road temp goes down to 37 degrees F one should be cautious and watch out because black ice is clear, not visible and undetectable to the naked eye. Almost always forms in very smooth, very glossy sheets but black ice patches are usually not longer than 6 m and patchy so some traction is available for the tires but not much. Roads are usually made out of asphalt and or concrete which emit energy very well. With an infrared camera, it can measures the amount of energy emitted by the road and can also measure its surface temperature. A camera with a refracted lens can detect radiation from different specific points from the road. These cameras can be used to tell workers where to apply salt or sand on highways and municipal roads. Infrared light or thermography is using a camera to see and measure the amount of thermal energy being radiated from an object. The infrared camera can detect heat and quickly convert it into an image or video and precisely measure the amount of heat coming from an object. The warmer the object the more heat it emits. These cameras can be used to prevent damage related to heat in pipes in homes for example but since infrared can detect anything that radiates heat, this technology could be used to detect any wildlife close by when driving. According to WARS (Wildlife Accident Reporting System) there have been approximately 4,700 car accidents including wildlife in North America since 1993. Weather conditions in North America, especially winters are hash and the roads are extremely treacherous with black ice causing many accident. The technology to detect wildlife on roads or nearby when driving has already been tested and used on some cars but adding the element of detecting black ice at the same time adds more protection and reassurance to drivers driving in bad road conditions. Using a flip down screen cover or an alarm, we could warn the driver when a patch of ice was coming up or when wildlife was close by. We would have to use emissivity and T reflection when looking for black ice, because the ice is going to be a smooth surface, therefore it is going to reflect whatever is in the background. We will even have to consider the reflection of the sky and or trees and anything in the surroundings because black ice is highly reflective. The angle of the camera and the speed of the car have to be considered so that we can get the information to the LCD or alarm to warn the driver so that they can have enough time to slow down and so that we don’t miss the ice or do not have the time to react to it. First off by finding the angles of field of view using the formula: 2 x the tangent of ½ the angle x distance and then finding the speed of the car in feet pr second. Finding the speed is only the first step of the formula which will show how this camera will work to detect not only wildlife but black ice as well. By using the formula of absorption, transmission and radiation, we have a good start to the end formula.
