Design and construction of an adjustable illuminance chamber for lux meter calibration

Abstract

Design and construction of an adjustable illuminance chamber for lux meter calibration, using a digital controller with the pole relocation technique, complying with the requirements of the Official Mexican Standard NOM-025-STPS-2008, used to obtain the degree of Master of Engineering Sciences, from Engineer José Federico Chong Flores, in The Tecnológico Nacional de México, Campus Ciudad Madero, in the division of graduate studies and research, December 2023. The luxmeters used to measure lighting conditions, are required by law to be calibrated by a standard-compliant (NMX-EC-17025-IMNC-2018) laboratory; in order to ensure the correct CONFORMITY ASSESSMENT, the measuring equipment must perfectly comply with the metrological characteristics of: error, reproducibility, repeatability, traceability. It is necessary to have a REFERENCE to compare and achieve a VERIFICATION and/or a CALIBRATION, the calibration of lux meters is carried out with the help of a PHOTOMETRIC BENCH, which involves a high-cost physical installation, with countless possibilities of mechanical error and exposed to human error, without any degree of portability.  The proposal is the construction of a portable photometric bench, for use on work bench for calibration, making use of LED technology and a microprocessor system, where a digital controller is used to compensate and maintain the selected values allowed by the standard, the luminous intensity and the wavelength, to serve as a reference and allow the possibility of verification or calibration of lux meters, of course after a calibration process in an accredited laboratory. The portable equipment, can be used in any work bench, without demanding the conditions that a photometric bench currently demands, the total lighting isolation and satisfactory compensates the values of temperature, humidity and illuminant conditions, just as to keep the wavelength defined by the illuminant A as a reference during all the tests of calibration or verification.