What is unique about NIR Cameras?
“Near-infrared” (NIR) is the portion of the electromagnetic spectrum directly adjacent to the visible range; therefore it cannot be perceived with the human eye. NIR-optimised industrial cameras are popular for applications that need to utilise this wavelength range, e.g. applications with poor light conditions, such as traffic monitoring. Until now, these applications were only possible with expensive CCD sensors.
Now, new CMOS technology can do the job, providing sensors with increased sensitivity in the near-infrared range over 850 nm. It achieves this through the application of a thicker substrate layer (as compared to a monochrome sensor) for the visible spectral range. With the previous standard CCD technology this was not possible; distinctive and expensive CCD sensors were necessary to exploit the NIR range. Now, the new CMOS technology has made NIR optimisation affordable, through a line of industrial cameras with excellent sensitivity in the near-infrared, which in turn has boosted their share on the machine vision market.
Do I need an NIR camera for my application?
Some application fields and inspection solutions require NIR for high wavelengths as well as for normal lighting, to record high-contrast images. Standard industrial cameras quickly reach their limits in that particular scenario, since they require very good lighting conditions to capture useable images. Setting up these light solutions adds tremendous cost and complexity, which in turn leads to rising system costs and deterioration of the price/performance ratio. Industrial cameras with NIR-optimised sensors greatly simplify life for manufacturers facing inspection tasks of this type.
Why use NIR Cameras?
Typical application examples are traffic monitoring installations that need to work in poor lighting conditions and at night, fruit and vegetable inspections to detect damaged spots using location-sensing spectroscopy, and the inspection of solar wafers through electro-luminescence.
Some advantages of NIR sensors are:
- Very good sensitivity in the infrared range
- High contrast in many difficult illumination situations
- High contrast due to special spectral characteristics of many inspection objects
- Favourable price compared to CCD cameras
- Proven production process and high quality