Laser Distance Measurement for High-Temperature Pipe Welds
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Solution Overview
Problem
Current technologies lack a high-accuracy method for measuring distortion in high-temperature states, making it difficult to detect cracks in pipes and welds accurately, which is crucial for determining repair and replacement timing.
Innovation Solution
A distance measuring system comprising a reflecting plate, a laser displacement gauge, and a processing device that measures changes in distance between welds and heat-affected zones, utilizing a semiconductor laser and a microcomputer-based processing unit to calculate remaining life and detect cracks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional distortion sensors are used to measure distortion in high-temperature states, then measurement can be performed, but measurement precision deteriorates due to inability to maintain high accuracy for long time in high-temperature environment
Solution Approach 1:
The patent introduces a reflecting plate as an intermediary component that is attached to the pipe or weld. The laser displacement gauge does not directly contact the high-temperature object but instead measures distance to the reflecting plate, which reflects the laser beam back to the gauge. This intermediary approach allows accurate measurement without exposing the sensor to harmful high-temperature conditions.
Solution Approach 2:
The patent replaces conventional contact-type distortion sensors with a non-contact laser displacement gauge that uses optical fields (laser beams) to measure distortion. This substitution eliminates the need for physical contact between the sensor and the high-temperature object, thereby maintaining measurement precision in high-temperature environments.
2Duration of action of moving object
If measurement time is extended to capture long-term distortion for crack detection, then more data is obtained, but measurement precision deteriorates due to sensor degradation in high-temperature conditions
Solution Approach 1:
The reflecting plate serves as a stable intermediary that can remain attached to the high-temperature object for extended periods without degrading. The laser displacement gauge performs measurements over time by continuously or periodically measuring the distance to the reflecting plate, enabling long-term monitoring while maintaining precision because the gauge itself is not exposed to high temperatures.
Solution Approach 2:
By using optical fields instead of mechanical contact sensors, the system enables prolonged measurement duration without the sensor degrading in the high-temperature environment. The non-contact nature of laser measurement allows continuous monitoring over extended periods while maintaining measurement accuracy.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate detection of cracks and determination of repair timing, reducing unnecessary repairs and maintenance costs by measuring expansion across welds and heat-affected zones even at high temperatures.
Implementation Method 1
a laser displacement gauge 52... utilizing a semiconductor laser
Implementation Method 2
a reflecting plate 50... measures changes in distance between welds and heat-affected zones
Data Source
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AI summary
[Solution] A distance measuring system includes: a reference member configured to be provided on a surface of a first pipe made of metal, the reference member serving as a reference for distance measurement; an attachment member provided on a surface of a second pipe, made of metal, connected with the first pipe through a weld; a distance sensor configured to be attached to the attachment member, to measure a distance to the reference member; and a measuring unit configured to measure the distance based on an output from the distance sensor.