The reflection of light is an optical phenomenon. A phenomenon in which light travels back to the original matter by changing the direction of its propagation at the interface as it travels to different substances. Light reflects off water, glass, and many other surfaces. When light changes direction of propagation at the interface between two substances and returns to the original substance, it is called reflection of light.

The principle of light reflection

Reflection of light

The Principle of Light Reflection

Reflection of Light

Infrared light, as a kind of invisible light, also follows the law of reflection of light, which can be verified from daily life phenomena: when using the TV remote control, sometimes we do not need to point the remote control at the receiving hole of the TV, or even to the wall to operate the TV. This is a reflection of infrared light.

Infrared thermal imager detects the temperature by detecting the infrared radiation of the object. When there is a relatively smooth mirror object (glass, steel plate, etc.) in the detection environment, the infrared radiation of the high-temperature object will be reflected. When the thermal imager detects at a certain Angle, the temperature anomaly of the smooth mirror object will appear, which is not the temperature anomaly of the thermal imager, but caused by its temperature measuring principle.

Glass Reflection

In this scene, there is a piece of glass forming a mirror, reflecting the infrared radiation emitted by people, so the figure also appears on the glass. Because part of the infrared radiation emitted by human is detected by thermal imager through the reflection of glass, what is reflected in the picture is the change of glass temperature.

How to Prevent This From Happening?

1. Try to avoid the appearance of smooth mirror objects in the detection environment to avoid the appearance of reflection effect;

2. Active box selection of tested objects:

The infrared thermal imager detection software supported by Yoseen Infrared can arbitrarily add the temperature measuring object, select the measured object through any polygon, only care about the temperature of the temperature measuring object, exclude the effect of reflection;

3. Add the shielded area

In addition to the active addition of temperature measurement objects, The detection software of Yoseen infrared thermal imager can also add the shielding area. When there is reflection phenomenon, which will affect the misjudgment, the influence of the fixed position or area in the picture can be shielded by adding shielding area.