In order to determine the irradiance profile of a directive source on a plane XY, we present an arrangement of geometry
similar to conventional scanners. It is formed by two vertical bases of a mobile rail. On this rail, a photodetector is
located, making it able to move from right to left, covering a mesh of 14x15 detection points.
The XY movements of the setup are determined by servo motors, which determine the resolution, but considering the
interest of researchers in this area, and the feasibility to use a table XY for the scanning, we implement its use as a part
of this meter. The detector is located at the corner of the mobile section. The height of the light source under test is
located at the central part of the described area.
The utilization of only one photo-detector was decided with the purpose of a higher homogeneity of the irradiance
measurements. The detector must have high stability and low noise. The resolution XY is determined by the movements
on the axes of a length determined by the DSPIC programming. The use of this device instead of commercial hardware
for data acquisition contributes to the low costs of the prototype. It was realized all the necessary tests for the generation
of reliable information, establishing the time needed to achieve the stability of the system, as well as the levels of noise
due to the presence of the detector and of the electronic elements.
This prototype has a very simple geometry and relatively low cost. It constitutes a good option to determine the
irradiance profile of directive sources.