Patent ID: 9146172
Filing Date: 2015-09-29
Classification: E03B,G01K,G01M,Y10T

Abstract:
1. A fluid leak detector for detecting leakage in a pressurized fluid system having a closed fluid conduit having an upstream portion and a downstream portion where fluid flows from the upstream portion toward the downstream portion, the fluid leak detector having a means for detecting the flow of fluid through said conduit comprising: a first sensor in thermal communication with the outside of said conduit and capable of sensing an ambient temperature of the fluid within said conduit, wherein said first sensor includes a first temperature sensing element; a second sensor in thermal communication with the outside of said conduit, wherein said second sensor includes a second temperature sensing element and a heater thermally coupled to the second sensing element; an adjustable Wheatstone bridge circuit consisting of the first and second temperature sensing elements and having a first output and a second output; a servo amplifier configured to drive the heater consisting of: an adjustable comparator consisting of: wherein the power transistor drives the heater in response to the difference in temperature between the first temperature sensing element and the second temperature sensing element: and wherein the adjustable comparator is configured to change state when the output of the power transistor exceeds a threshold, and wherein said first sensor is positionable at any location along said closed fluid conduit and said second sensor is positionable downstream from said first sensor.