Implement Industry Ideas
  • Computerized stations for testing NVDs / NIMAX


Article: 00249799

Computerized stations for testing NVDs / NIMAX

Computerized test stations can enable measurement of important objective parameters like modulation transfer function MTF and signal to noise ratio SNR. These parameters cannot be measured by typical non-computerized stations. Further on, use of computer technology in testing NVDs can potentially reduce differences between methodology of testing NVDs and methodology of testing electronic imagers like thermal imagers, and visible/NIR cameras. Nowadays, there is basically no major technical obstacles to use well matured methodology of testing visible/NIR cameras also for testing NVDs. This scenario would potentially enable easy comparison of performance of NVDs and low light TV cameras. NIMAX test station works as a set of two image projectors that project images of standard targets into direction of tested night vision devices. The latter devices create output image that is later evaluated by human observer or with help of more objective measuring tools (luminance meter, high-res video camera, or digital still camera). The first projector of small aperture optics is used to test night vision goggles/monoculars. The second projector of big aperture optics is used to test night vision sights/binoculars. Light source MIL standards recommend to use a calibrated tungsten filament lamp of 2856K color temperature as a radiation source. It is technically difficult to develop a reliable, long life, 2856K color temperature tungsten filament light source that enables regulation of light intensity in wide range. Therefore typical test stations for testing night vision devices offered on market are built using a single monochromatic LED light source. Such test stations are calibrated to simulate 2856K color temperature light source for one specific type of night vision device (typically built using Gen 3 tubes and Class A filter). Measurement accuracy significantly deteriorate when night vision devices of different type are tested. NIMAX test station is built using more advanced concept. The station is built using two light sources that can work in two modes: a)halogen bulb of 2856K color temperature source and b)monochromatic LED light source. Halogen source is used during measurement of photometric parameters; monochromatic LED source during measurement of imaging parameters. Therefore NIMAX station enables accurate measurement of photometric parameters (like brightness gain) of all types of night vision devices. Next, NIMAX station can be checked and re-calibrated by advanced photometric laboratories in many countries because these stations use classical photometric light source. At the same time life time of the test station was significantly extended due to use of halogen source only for measurement of photometric parameters. Test capabilities NIMAX test station enables measurement (or checking) of a long list of parameters that can be divided into six main groups 1. Typical tests: resolution (center, peripheral, high level), screen quality (dark spots), brightness gain, field of view, ocular diopter range. 2. Maintenance checks: Operational defects (shading, edge glow, flashing,/flickering/intermittent operation, emission points); Cosmetic defects (Dark Spots, Bright Spots, Fixed-Pattern Noise, Chicken Wire, Image Disparity, Output Brightness Variation, Image Distortion), 3. Binocular tests: collimation error, gain disparity. 4. Expanded tests: Minimal Resolvable Contrast, magnification and EBI (option). 5. Electrical tests: power consumption, current. 6. Advanced tests: MTF, SNR. NIMAX test station enables recording of test results and video recording of images generated by tested night vision devices. Special software that enables presentation of recorded videos from several tested NVDs at the same time at PC screen is a part of NIMAX test station.


Other items

In this category | In this category, (INFRAMET)

Leave request for price calculation right now, we will send you best prices.