System with microcontroller for photometric measurements in technological installations and optical communications systems

The system presented in this paper is intended to be used in applications where is necessary to evaluate very accurate the illuminance and luminous emittance which is equivalent with measurement of luminous power per unit area. The novel implementation of the proposed system is based on AVR Atmega128 microcontroller which realizes the majority of the processing functions excepting the signal conditioning from the optical sensor. The photometric system has an extended measurement range of 0-100Klx divided in three domains of: 0-1Klx, 10lx-10Klx and 100lx-100Klx. The system can automatically select the proper scale during the measurements. Also the system is equipped with an RS232 serial interface that allows to saving the results of the measurements on hard disk drives of a personal computer for further analyzes of the obtained data. The system can operate independently, powered from a battery and displaying information on an LCD.