How does a thermal imaging camera work

How does a thermal imaging camera work

Seeing is believing, but the inherent limitations of the human eye prevent us from seeing visible
light outside a narrow range. Infrared energy is the electromagnetic radiation emitted by the sun,
as well as every object and living thing on Earth, and something that can only be viewed by
humans using a thermal imaging camera (TIC). Infrared radiation falls just outside the visible
light wavelengths at about 750nm (nanometers) and is part of a series of longer frequencies;
Along with terahertz, microwaves and radio waves. By simply connecting a CompactPRO to your phone
and loading the app, your spectral sensitivity will be enhanced to discover a world you've never
seen before.

How it works

Any thermographic camera works by measuring the amount of infrared energy that is emitted,
transmitted and reflected from an object. The use of small vanadium oxide sensors, known as
microbolometers, allow thermal cameras, such as the RevealPRO, to operate portably, and do not
need to rely on stationary cryogenic cooling to work properly. The camera takes a surface
temperature measurement of the heat from an object and projects it as an image on the screen
called a thermogram. While this feature makes it possible to identify cool or hot spots beneath
a surface, it does not, as is often misguided, give users X-ray vision or the ability to
literally see through a wall. Black bodies have a baseline emissivity of 1, and provide a
template against which other degrees of radiation are measured. An algorithmic function is
then used to calculate and expand multiple sources of infrared energy around the object and
create the image that is then displayed on the LCD screen.

Camera lens

Unlike their cousins ​​the optical cameras, thermal imagers do not rely on glass focus lens as it
blocks long infrared light. Until recently, IR cameras historically relied on lenses made from
specialized materials such as Germanium or Sapphire crystals, which are fragile and expensive
to produce. Chalcogenide glass is a newer and cheaper material that enables the lower cost of
entry of thermal cameras to the market and into the hands of the customer. The material is
ideal for lenses as it allows the transmission of a wide range of electromagnetic frequencies
across the surface. Rectangular light sensing pixels at the focal point of the lens, called
Focal Plane Arrays, (FPAs) help to receive and focus the infrared energy to the microbolometer.

Show

Images are usually monochromatic or show a false color scheme to reveal any variations in
temperature. The camera assigns each individual pixel from a 76,800-pixel display to represent
a temperature. After it is calculated, the pixels are assigned colors, which build the
resulting image on the screen. Dark shades of blue, purple and green are usually used in the
thermal color scheme to represent cooler temperatures, while bright colors (yellow, orange, red)
often indicate the presence of heat. Infrared devices such as the RevealPRO or the Shot Pro
offer a variety of unique filters to give users flexibility, and a broader visualization
platform for identifying temperature differences.

Differences Between Night Vision Devices (NVD)

While both night vision scopes and thermal imagers often fall under the umbrella term "NVDs,"
they work in very different ways. Traditional night vision scopes use a vacuum tube
(aka image intensifier) ​​that increases the low levels of ambient light to create
distinguishable images and render them in different shades of green. Extensive use in
military and law enforcement circles, they are valuable tools for surveillance and suspect
identification. However, the achievement of well-defined images is highly dependent on the
presence of existing ambient light. Viewing a night vision in a bright dark room will provide
little clarity. Thermal cameras, on the other hand, do not require light and can scan through
complete darkness, as well as smoke, fog and down. While NVDs provide more "realistic" and
controlled images, their use outside of the military complex rarely remains. With more and
more applications, thermal cameras are using their colorful, dramatic contrasts to remotely
illuminate objects and numbers and draw attention to a wide variety of settings.