Stemmer Imaging's latest camera offering, the JAI AD-081CL, features two monochrome progressive scan CCD sensors mounted to a custom-designed optical prism. The prism-based design enables the camera to simultaneously capture two channels of 30fps video of the same field of view to within one-quarter pixel accuracy. A choice of operating modes allows the camera to be used for high dynamic range, high-speed operation or particle imaging velocimetry.
Particle Imaging Velocimetry (PIV) is a planar optical measurement technique which provides a means of measuring the velocity of seeded particles (~1-50µm in air) in the flow of interest. Applications include vortex forming in artificial heart chambers, combustion analysis in engines, and airflow studies in wind chambers. With a single CCD camera, the laser illumination is pulsed and two sequential images are captured and analysed to track particle measurement. The dual sensor AD-081CL, however, features a unique PIV mode, which allows the camera's two-channel operation to capture three closely spaced images on a single trigger instead of two. This provides 50 per cent more data for improved analysis of ultra-fast events.
Independent control of shutter speed and/or gain for each channel of the AD-081CL provides the opportunity for wide dynamic range operation. This is especially useful in inspection applications where there is a particularly bright light background, such as LED inspection or welding. One channel is adjusted for the bright output, while the other channel is tuned for lower light output. The two images can then be analysed separately or combined to produce a dynamic range nearly double the normal CCD response. This enables the camera to achieve dynamic range levels as high as 20-bits per pixel (~120dB) in a linear fashion that avoids the noise, shutter, and compression issues found in other types of cameras.
The versatile AD-081CL can also operate at an effective frame rate of 60fps. This is achieved by interleaving the images from the two sensors into a single output stream. This high-speed/low-noise mode does not increase in the clock frequency of the camera itself, thus keeping clock noise to an absolute minimum.
Each sensor has 1,024 x 768 pixel resolution and 8- or 10-bit pixel depth. The camera features two configurable Camera Link outputs, allowing single-cable operation or separate cables for each channel. Other features include partial scanning and vertical binning capabilities, as well as analogue video output to support auto-iris lenses.