TopIntroduction
The necessity of illumination sources, satisfying specific requirements, especially considering low power consumption has produce the continuous appearing of new illumination sources in the market. To characterize them, it is necessary to account with several technological tools, such as luminous flux meters, intensity of illumination meters, goniophotometers and software developed to visualize the luminous intensity distribution. Mathematical approaches to calculate the photometric quantities are also needed.
In the development of goniophotometers (Muñoz, et al., 2013) and in the experimental tests to guarantee their reliability (Sametoglu, 2008), several factors must be considered. Calibration is one of the critical aspects that support reliable operation of illuminance and luminance meters (Fiorentin & Scroccaro, 2010). The automation and implementation cost are also decisive (Cruz-Colon et al., 2012), especially for prototypes development.
In the case of Light Emitting Diodes (LED) sources, the orientation effect is not presented because their emission is independent of their orientation meters (Fiorentin & Scroccaro, 2008). LEDs are lambertian sources. In the case of LED tubes, the luminous intensity patterns of most sources analyzed in (Ryckaert, 2012) are approximately lambertian.
A Lambertian source is defined as one in which the brightness (or luminance) is independent of angle, in other words the off-axis luminance is the same as on-axis. Such a source has intensity vs. angle profile that falls off as the cosine of the angle. Historically, many LED sources have had nearly Lambertian beam distributions, simplifying certain calculations (Osram, 2011).
The photometry, produced by the corresponding photometric report of the luminary is widely used by the luminaries’ manufacturers and they are involved in the design process or special applications. The distribution curves of the illumination intensity are also called candlepower distribution curves. Mexican software has also been developed in order to generate these reports for interior lightening (SIMCLI Software, 2012), (García Flores, 2005), but about hardware to measure the illumination level; the information is not so wide. In Colombia, the software LUMENES has been developed to illustrate that the selection of the adequate illumination source depends of several factors such as physical, economical, etc.) (Informe Ejecutivo, 2008)
In (Fiorentin& Scroccaro, 2008), a goniometer installed in the Photometric Laboratory of the Padova University is described and used to realize measurements of luminous flux.
At commercial level, different types of meters have been developed to provide an empirical base of information for specific characteristics, such as: photometers and portables intensity light meters.
In this article, the design of each block of the complete adjustable and automated system prototype of irradiance meter, where the use of programming and software design are fundamental. The improved semi-spherical prototype is developed on the base of a single Photodiode for Visible Light BS520 with spectral sensitivity characteristics akin to that of human eye, which was obtained from a photocopier, inside the package AE (Automatic Exposure) sensor.
The development of a Graphical User Interface (GUI) is presented. The advantage of this GUI is given by its capability to connect at irradiance meter or goniophotometers to receive the produced data and to generate the light distribution curves without the use of additional graphical software.