Tuesday, May 24, 2011

Stop Thermal Imaging

Conduct a simple experiment to determine whether an infrared device can see through your clothing.


Sight is due to electromagnetic waves (light) reflecting off objects and into eyes. However, eyes can only see electromagnetic waves with a wavelength of 380 to 400 nanometers. This, in general, limits sight to outer surfaces. Other wavelengths of light are able to penetrate thin materials, and if a device can "see" at these levels, then it may be possible to see through an object. One such device is a thermal imaging camera, and today there is a great deal of concern about people using these devices to see through clothing.


Instructions


1. Understand that thermal imaging works in the part of the electromagnetic spectrum known as the infrared region. Infrared radiation is like light, but it is emitted by an object that is warm, such as a person's skin. Infrared radiation travels through some thin types of material.


2. Test your clothing yourself to determine whether thermal imaging will penetrate it. Place the item of clothing that you want to test on a hanger.


3. Stand facing the front of your television at a distance of around 6 feet. Hold the coat hanger out in front of you at arm's length.


4. Aim the remote at your television with the item of clothing between the television and the remote. Press the remote up against the item of clothing and press a button on the remote, for example "Channel Up." If the TV responds, you know that infrared radiation has passed through the clothing, and thus an infrared camera could see through it as well.


5. Repeat for different items of clothing as well. Take note of what allows infrared and what does not. Clothing articles that do not allow transmission are those that will stop thermal imaging devices from invading your privacy.


6. Dress in layers if you are going to be exposed to thermal imaging. Very thin, cotton-like materials are easily penetrated with infrared, but the more layers you wear, the less likely transmission becomes. Thick and heavy fabric also blocks the infrared radiation, stopping people from seeing through your clothes. Color is important as well, and darker colors will block infrared more readily than lighter colors.







Tags: item clothing, thermal imaging, determine whether, electromagnetic waves, infrared more, thermal imaging, through clothing