High precision technique of measuring the reflectance of reflective materials
A new method of reflectivity measurement is proposed and tested in this Ph.D. study. The method employs fast rotating reference mirror and certain geometry configuration to alternately deliver the light via a sample mirror or by passing it to a photo detector. It has proved to reach a precision of 2...
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
2001
|
| Subjects: | |
| Online Access: | http://eprints.utm.my/6816/ http://eprints.utm.my/6816/1/LimBoonHanPFKE2001.PDF |
| _version_ | 1848891352620728320 |
|---|---|
| author | Lim, Boon Han |
| author_facet | Lim, Boon Han |
| author_sort | Lim, Boon Han |
| building | UTeM Institutional Repository |
| collection | Online Access |
| description | A new method of reflectivity measurement is proposed and tested in this Ph.D. study. The method employs fast rotating reference mirror and certain geometry configuration to alternately deliver the light via a sample mirror or by passing it to a photo detector. It has proved to reach a precision of 2 x lo4 reflectance unit. The precision is at least ten times better than that of conventional reflectometer used in solar energy applications. With good repeatability, the durability test of mirrors is camed out for only one month enabling significant specular reflectance losses of mirrors to be observed instead of more than a year in the conventional case. The reflectometer has provided solutions to few problems that limit the conventional reflectometer. Firstly, the time interval between the collection of reference signal and sample signal is short, therefore, this can reduce the effect due to the changes of environment conditions, particularly, the intensity fluctuation of light source and others. Secondly, by taking advantage of the short measurement time, a large number of readings can be made to suppress the noise level. Thirdly, the value of the reflectance of the reference mirror is not required. In the system, an accurate positioning of laser beam on the photo detector is achieved by a position sensor using a pair of dual cells that acts as an optical lever as well as a position transducer for the feedback system. |
| first_indexed | 2025-11-15T20:56:36Z |
| format | Thesis |
| id | utm-6816 |
| institution | Universiti Teknologi Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T20:56:36Z |
| publishDate | 2001 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | utm-68162018-09-27T04:03:51Z http://eprints.utm.my/6816/ High precision technique of measuring the reflectance of reflective materials Lim, Boon Han TK Electrical engineering. Electronics Nuclear engineering A new method of reflectivity measurement is proposed and tested in this Ph.D. study. The method employs fast rotating reference mirror and certain geometry configuration to alternately deliver the light via a sample mirror or by passing it to a photo detector. It has proved to reach a precision of 2 x lo4 reflectance unit. The precision is at least ten times better than that of conventional reflectometer used in solar energy applications. With good repeatability, the durability test of mirrors is camed out for only one month enabling significant specular reflectance losses of mirrors to be observed instead of more than a year in the conventional case. The reflectometer has provided solutions to few problems that limit the conventional reflectometer. Firstly, the time interval between the collection of reference signal and sample signal is short, therefore, this can reduce the effect due to the changes of environment conditions, particularly, the intensity fluctuation of light source and others. Secondly, by taking advantage of the short measurement time, a large number of readings can be made to suppress the noise level. Thirdly, the value of the reflectance of the reference mirror is not required. In the system, an accurate positioning of laser beam on the photo detector is achieved by a position sensor using a pair of dual cells that acts as an optical lever as well as a position transducer for the feedback system. 2001-10 Thesis NonPeerReviewed application/pdf en http://eprints.utm.my/6816/1/LimBoonHanPFKE2001.PDF Lim, Boon Han (2001) High precision technique of measuring the reflectance of reflective materials. PhD thesis, Universiti Teknologi Malaysia, Faculty of Electrical Engineering. http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:62394 |
| spellingShingle | TK Electrical engineering. Electronics Nuclear engineering Lim, Boon Han High precision technique of measuring the reflectance of reflective materials |
| title | High precision technique of measuring the reflectance of reflective materials |
| title_full | High precision technique of measuring the reflectance of reflective materials |
| title_fullStr | High precision technique of measuring the reflectance of reflective materials |
| title_full_unstemmed | High precision technique of measuring the reflectance of reflective materials |
| title_short | High precision technique of measuring the reflectance of reflective materials |
| title_sort | high precision technique of measuring the reflectance of reflective materials |
| topic | TK Electrical engineering. Electronics Nuclear engineering |
| url | http://eprints.utm.my/6816/ http://eprints.utm.my/6816/ http://eprints.utm.my/6816/1/LimBoonHanPFKE2001.PDF |