Fluorescent optical liquid level sensor

Patent · Mon Jan 01 00:00:00 EST 2001

OSTI ID:873488

Weiss, Jonathan D ^[1]

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1. Albuquerque, NM

A liquid level sensor comprising a transparent waveguide containing fluorescent material that is excited by light of a first wavelength and emits at a second, longer wavelength. The upper end of the waveguide is connected to a light source at the first wavelength through a beveled portion of the waveguide such that the input light is totally internally reflected within the waveguide above an air/liquid interface in a tank but is transmitted into the liquid below this interface. Light is emitted from the fluorescent material only in those portions of the waveguide that are above the air/liquid interface, to be collected at the upper end of the waveguide by a detector that is sensitive only to the second wavelength. As the interface moves down in the tank, the signal strength from the detector will increase.

• Research Organization: Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
• DOE Contract Number: AC04-94AL85000
• Assignee: Sandia Corporation (Albuquerque, NM)
• Patent Number(s): US 6172377
• OSTI ID: 873488
• Country of Publication: United States
• Language: English

Related Subjects

fluorescent
optical
liquid
level
sensor
comprising
transparent
waveguide
containing
material
excited
light
wavelength
emits
upper
connected
source
beveled
portion
input
totally
internally
reflected
air
interface
tank
transmitted
below
emitted
portions
collected
detector
sensitive
moves
signal
strength
increase
sensor comprising
internally reflected
fluorescent material
level sensor
input light
light source
liquid level
signal strength
liquid interface
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