Variable area flow rate meter using optical sensing of float position in the duct
First Claim
1. A flowmeter for providing a signal indicating fluid flow rate through the flowmeter, said flowmeter of the type having a vertical, tapered duct defined by a duct wall and having an axis extending the length of the duct, a first opening for receiving flow of fluid whose flow rate is to be measured, and a second opening from which the fluid exits the duct, and a float shifting position along the duct axis within the duct and whose vertical position in the duct indicates the fluid flow rate, said flowmeter further comprising:
- a) a window forming a portion of the duct wall in alignment with the duct axis, said window transparent to light and positioned adjacent to one opening of the duct;
b) a light source external to the duct and adjacent to the window, and transmitting light through the window toward the float;
c) a feature of the float that returns to the window a portion of the light shining on the float; and
e) a light sensor external to the duct and receiving through the window, light returned from the float previously transmitted toward the float, and providing a sensor signal indicating the level of light received by the light sensor.
1 Assignment
0 Petitions
Accused Products
Abstract
A flowmeter has a variable area, vertically-oriented duct through which flows fluid whose flow rate is to be determined. A float in the duct assumes a position in the duct that depends on the flow rate of fluid in the duct. A window is located at an end of the duct in alignment with a longitudinal axis of the duct. A transducer unit projects a light beam through the window and along the axis toward the float. The transducer includes a light sensor that detects light returned by the float by reflection or some other mechanism to the transducer unit. The intensity or other characteristic of the returned light indicates the position of the float in the duct, from which the fluid flow rate may be determined.
34 Citations
10 Claims
-
1. A flowmeter for providing a signal indicating fluid flow rate through the flowmeter, said flowmeter of the type having a vertical, tapered duct defined by a duct wall and having an axis extending the length of the duct, a first opening for receiving flow of fluid whose flow rate is to be measured, and a second opening from which the fluid exits the duct, and a float shifting position along the duct axis within the duct and whose vertical position in the duct indicates the fluid flow rate, said flowmeter further comprising:
-
a) a window forming a portion of the duct wall in alignment with the duct axis, said window transparent to light and positioned adjacent to one opening of the duct; b) a light source external to the duct and adjacent to the window, and transmitting light through the window toward the float; c) a feature of the float that returns to the window a portion of the light shining on the float; and e) a light sensor external to the duct and receiving through the window, light returned from the float previously transmitted toward the float, and providing a sensor signal indicating the level of light received by the light sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
Specification