A novel prototype light meter has been developed by researchers in New York. Published today in the Institute of Physics journal, Measurement Science and Technology, this new retinal flux density meter will provide an affordable tool for measuring light at all levels and might ultimately lead to new standards to improve both energy efficiency and safety at night.
The retina in the eye detects light using cells called rods and cones. At high light levels, such as in daylight, the cones detect the light, but when there is very little light, such as on a moonless night, the eye uses the rods for vision. Rods are positioned away from the central axis of the retina which means that in very low light you have to look slightly to the side of something in order to see it. Current ways of measuring how much light is present, for setting standards in offices and schools for example, only relate to cones. This means that in low light levels, where both rods and cones are operating, measurements of how much light is present are inaccurate. This is reflected in the practical and inexpensive nature of current more primitive light meters.
Now researchers from the Lighting Researcher Center at Rensselaer Polytechnic Institute in Troy, New York have developed a new light meter that accurately characterises this shift from rod to cone vision and that is cheaper and less bulky than the very expensive and sensitive instruments that are only practical for use in a laboratory.
Alice Bows | alphagalileo
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Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
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