Wavelength regions in thermal cameras

RasaAndishan is proud to introduce the first Iranian-made industrial thermal camera in the long-wave infrared band. This advanced product was developed with local technology and designed to cover 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 other circuit components.

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

Thermal cameras generally work in two wavelength bands: (3–5 µm) and (8–12 µm). Both bands can be used for (Passive) thermal imaging. Some points about these two bands:

• The solar radiation in the (3–5 µm) band is about 25 W/m². In the (8–12 µm) band, it is about 1.5 W/m². That is why, on sunny days, sunlight can significantly change the thermal image in the first band (3–5 µm), but it has no major effect on the image in the (8–12 µm) band.
• At ambient temperature and for the same temperature difference, the available energy in the (8–12 µm) band is 30 times that in the (3–5 µm) band. As a result, the signal-to-noise ratio improves and you see a better image.

• The smaller the NETD, the better the system's sensitivity. Because NETD is smaller in the 8–12 µm region, good sensitivity can be achieved there.

• If you want to image targets much hotter than their surroundings (such as a rocket exhaust), a 3–5 µm camera is the better choice, because the emission peak of such targets lies at shorter wavelengths, where their radiated power is high.
• Without a specific application in mind, neither band can be called better than the other. That said, the (8–12 µm) band easily meets most needs. According to Wien's displacement law, the peak radiation wavelength of any object depends on its temperature and is given by the following formula: T (temperature in kelvin), wavelength (in micrometers) = 2890 / T. For example, at human body temperature, the wavelength is 9.32 micrometers.

Which band is right for your work?

If you want to monitor equipment at ambient temperature, the 8–14 μm band usually covers most needs. The RasaAndishan thermal camera works in exactly this long-wave band. Sunlight has no major effect on the image in this band. So you get a more stable image even on sunny days.

The company's thermal cameras read temperatures from 20 to 2500 °C. This range suits metal melting, cement production and furnace monitoring. The temperature range can also be customized on request. To see the models and download the catalog, visit the Iranian-made thermal camera page. For the physics of these wavelengths, read the Infrared radiation article on Wikipedia.