Thermal camera performance

RasaAndishan is proud to present the first Iranian-made industrial thermal camera for the long-wave infrared band. This advanced product was developed with local technology and designed to meet a wide range of industrial, research and security needs.

Key features:

• Resolution and spectral range: A sensor with 640 × 480 pixel resolution, made in France (today's RA-ThermaPro-640X camera uses a different sensor with 640 × 512 pixel resolution), and a spectral response of 8 to 14 microns in the long-wave infrared band.
• Temperature range: Operating temperature of the camera itself (ambient temperature at the installation site): ⁦-40⁩ to ⁦+85⁩ °C.

• A sensor with NETD below 40mK and a 17 µm pixel pitch, for images with outstanding sharpness and detail and low thermal noise.
• High processing speed: a 40 Hz imaging rate, suitable for real-time applications and detailed analysis.
• Support for multiple colour palettes: including Rainbow, IronBow, BlackHot and Normal to optimise image display according to user requirements.
• Fast, robust connectivity: via a port USB3 for a stable connection and high-speed data transfer to the computer.
• Temperature calibration: precise adjustment of the temperature range to meet each client's specific requirements.
• Extensive customization: because the technology is developed in-house, the device can be customized for different industries.

Built on Iranian technical expertise, this camera offers a precise answer to diverse needs in the industrial, military, medical and research sectors. Contact us for more information or to place an order.

The figure below shows a thermal image of the electronic board of a high-speed camera. The regulator and the image sensor are much hotter than the rest of the circuit.

Thermal images in the IronBow, RainBow, WhiteHot, and BlackHot palettes, captured with the RA-ThermaPro-640X camera.

To see objects on the ground, the electromagnetic waves emitted (reflected) from the object's surface pass through the surrounding air and reach the camera. Air is a mix of various gases, water vapor, and suspended particles. So it absorbs some of these waves and scatters some. How strong this effect is depends on the wavelength used. Along the propagation path, conditions such as gas composition, wind, temperature, and other weather conditions can change. That is why analyzing these effects is complicated.
What matters for seeing an object is its contrast against the background. The farther you are from the viewing point, the more the weather conditions reduce this contrast. The maximum distance at which you can see an object in the visible band (at a wavelength of 550 nm) depends on the weather. In the visible band, however, absorption is negligible.
Above the sea surface, there is a considerable amount of water vapor and moisture. In the visible band, the main factor that reduces range is scattering. As long as water vapor stays in molecular form, it has little effect on scattering. But once it forms larger particles such as fog and cloud, it affects the range.
The atmosphere places major limits on the performance of electro-optical systems. In fact, the propagation medium can be seen as one of the most basic parts of an optical system. Today, the quality and capability of detection systems and radiation sources such as lasers have improved greatly. That is why the main limit on system performance is usually the atmosphere.

The main atmospheric disturbances that affect radiation transmission and the performance of a thermal imaging system are:
1- Attenuation of radiation (absorption, scattering)
2- Background (ambient) radiation in the infrared region
3- Deviation from the true target position
4- Radiation modulation

Of the key factors above, attenuation of radiation has the greatest effect and limits the range of these systems. Absorption and scattering in the atmosphere are caused by the particles in it: molecules of various gases, dust particles, rain, moisture, and so on. How much these particles affect the radiation depends on their density, temperature, pressure, and size and, most importantly, on the wavelength passing through.
The atmosphere does not transmit all wavelengths equally. Transmission is high only in certain bands, where it does not limit the system. The bands (0.4 to 1.5, 1.5 to 2.5, 3 to 5, and 8 to 12 µm) are the ones with significant transmission. These bands can be used for electro-optical systems. Of these, only the (3–5 and 8–12 µm) bands are suitable for building and using (passive) infrared imaging systems, that is, thermal imagers. The reason is that objects at ambient temperature emit most of their radiation in the mid- and long-wave infrared (with a peak near 10 microns), and in these two windows the atmosphere absorbs only a small part of it. In the Earth's atmosphere, fog, and smoke, infrared radiation is absorbed less than visible light. That is why these cameras can also be used in such poor weather conditions.

How does this help you in practice?

The atmosphere limits the range of every imaging system. That is why the choice of wavelength band matters so much. The RasaAndishan thermal camera works in the 8–14 μm band. This band is one of the two windows where the atmosphere absorbs less radiation.

Fog and smoke absorb infrared radiation less than visible light. So this camera stays useful in bad weather too. The furnace version of this camera reads the temperature of the melt and the flame in a glass-melting furnace. See its specifications and catalog on the Iranian-made furnace thermal camera page.

If you want to learn more, the Atmospheric window article on Wikipedia is a good place to start.