Below is an excerpt from the interview, you can read the full interview here: http://www.azooptics.com/Article.aspx?ArticleID=1058.
BE: What considerations should potential customers take into account when looking to purchase NVIS measurement equipment?
RA: It comes down to the accuracy of the measurement. Customers must be able to rely on the measurement results produced by their NVIS measurement system. Inaccuracies in measured data can be very costly. An NVIS measurement system that erroneously reports high NVIS radiance levels can force a customer to over-engineer their lighting product.
Conversely, a system that reports inaccurately low NVIS radiance levels can create problems when the product is integrated into the cockpit system, when it is often too late to address the problem. False failure reports are often caused by inadequate sensitivity or poor spectral purity.
NVIS radiance measurements are one of the most difficult lighting measurements to make. NVG’s are highly sensitive because they must amplify the limited light available in typical night time scenes, so it is critical that the NVIS radiance from lighting sources in the environment are lower than the night scene levels.
To measure these low radiance levels, NVIS measurement equipment must be even more sensitive than the NVG’s in order to report accurate radiance levels. The measurement equipment must also exhibit high levels of spectral purity because the weighting functions defined in the MIL standard are wavelength dependent and the weighting values change rapidly from the visible to near IR regions.
Trying to select an NVIS measurement system based solely on data sheet specifications can be misleading, if the measurement system supplier is not capable of producing consistent quality. The experience of the company that’s providing the measurement equipment is important to consider, as is third-party accreditation to laboratory standards like ISO/IEC 17025 .
Click here to read the full interview: http://www.azooptics.com/Article.aspx?ArticleID=1058.