The design and implementation of a rotation-type goniophotometer
| Autor: | Wei-Jen Wang, 王偉任 |
|---|---|
| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 This study designed and implemented a goniophotometer for measuring the intensity of a small-size light source in zenith angle (θ) and azimuthal angle (φ). A half-hemisphere shell of 15-cm radius was designed and manufactured with a 3D printer. There are 30 photodiodes on the shell as light sensors so that the zenith angle resolution is 3°. A 4096-step step motor loaded with a light source horizontally rotates so that the azimuthal angle resolution can be less than 0.1°. The light source was driven by 100 Hz square wave. The photo-current generated by a light-illuminated photodiode was converted into voltage signal with a trans-impedence amplifier. Voltage signal was converted into digital signal after a two-stage voltage amplifier. After calibration, the relative light intensity was detected from the digital signal. The design of amplifiers and calibration process are described. Two measurement examples of light emitting diodes were shown. In comparison with commercially available goniophotometer, the goniophotometer designed in this study has the potentials of small size, low cost, and short measurement time. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|