28 September 2011 Optical liquid-level sensor using a collimator in a pipe with small holes
Author Affiliations +
Abstract
To measure a level of a flammable liquid, optical sensing methods have been reported more effective than other methods based on mechanical and electrical methods. This paper reports a new method that uses a collimator and a pipe to measure the liquid level. The presented liquid-level sensor consists of a gradient-index lens (GRIN lens), a metal pipe with small holes, and a floating buoy as a mirror. The liquid in the tank flows into the pipe through small holes and the floating buoy coated with aluminum will float over the liquid. The light collimated by a GRIN lens will be reflected at the floating buoy, which operates like mirror. The light reflected from the mirror is refocused through the GRIN lens and is varied as a function of the liquid distance. It is a simple design using a pipe to collect easily the. The experimental result was obtained using a pipe with the height of 2 m and width of 10 mm. The power loss was decreased with the ratio of 30 dB/m. This low-cost configuration easily collects the reflected light from the liquid surface without complicated aligning.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Cherl-Hee Lee, Jonghun Lee, Jeon-Il Moon, Kwang Taek Kim, "Optical liquid-level sensor using a collimator in a pipe with small holes", Proc. SPIE 8185, Electro-Optical and Infrared Systems: Technology and Applications VIII, 81850T (28 September 2011); doi: 10.1117/12.897974; https://doi.org/10.1117/12.897974
PROCEEDINGS
6 PAGES


SHARE
KEYWORDS
Liquids

Sensors

Collimators

Mirrors

GRIN lenses

Fiber optics sensors

Gradient-index optics

RELATED CONTENT

Diaphragm based high sensitive FBG pressure sensor
Proceedings of SPIE (June 22 2013)
High sensitive FBG pressure sensor using metal bellows
Proceedings of SPIE (September 18 2013)
Mirror grown on optical fiber ends
Proceedings of SPIE (August 13 1998)
Principle and the application of an etched fiber-optic sensor
Proceedings of SPIE (December 04 1998)

Back to Top