Browse Prior Art Database

Liquid Level Indicator

IP.com Disclosure Number: IPCOM000097195D
Original Publication Date: 1962-Jun-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 22K

Publishing Venue

IBM

Related People

Freeman, ME: AUTHOR

Abstract

The device indicates the presence or absence of a specified fluid level. Light source 1 is mounted at one end of bent plexiglass rod 2 and photocell 3 is mounted at the other end. When the rod is surrounded by air, light rays from the source enter the rod and are totally reflected off the walls, so that they follow the rod and strike the photocell.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Liquid Level Indicator

The device indicates the presence or absence of a specified fluid level. Light source 1 is mounted at one end of bent plexiglass rod 2 and photocell 3 is mounted at the other end. When the rod is surrounded by air, light rays from the source enter the rod and are totally reflected off the walls, so that they follow the rod and strike the photocell.

When the elbow or bend of the rod is immersed in fluid, however, the critical angle is much greater because of the different index of refraction. A large part of the light is refracted through the walls into the fluid. Thus, in the presence of fluid, the photocell remains in the dark condition.

The index of refraction of the liquid must be greater than the index of refraction of the rod.

1

Page 2 of 2

2

[This page contains 1 picture or other non-text object]