Optical Dilatometer Self-Aligning Carrier Reference
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Solution Overview
Problem
Existing optical dilatometers have complex alignment requirements for optical systems and samples, making them difficult to handle and use effectively for measuring linear thermal expansion.
Innovation Solution
A simplified optical dilatometer design featuring a light source and collimator on one side of the furnace, with a sensor on the opposite side to detect the sample's length via shadow images, using a high-performance GaN LED and telecentric optical system, and a cylindrical furnace with removable parts for easy sample access and precise temperature control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical systems are aligned to measure sample length, then measurement precision is improved, but device complexity and ease of operation deteriorate due to complex alignment requirements
Solution Approach 1:
The system uses the sample carrier itself as the reference object for measurement. The carrier has a known geometric structure with reference marks that automatically provide the measurement reference frame, eliminating the need for separate alignment procedures. The optical system measures the sample position relative to these fixed reference marks on the carrier, making the system self-aligning and easy to operate.
Solution Approach 2:
The sample carrier acts as an intermediary element between the optical measurement system and the sample. It provides a stable reference framework that simplifies the measurement geometry. By measuring the sample position relative to the carrier's reference marks rather than requiring absolute alignment between optical systems and sample ends, the carrier mediates the measurement process and reduces alignment complexity.
2Measurement precision
If optical systems are aligned to measure sample length, then measurement precision is improved, but device complexity worsens
Solution Approach 1:
The measurement system becomes self-sufficient by using the sample carrier's inherent geometric structure as the reference. The carrier's reference marks are fixed relative to the carrier body, providing a stable measurement framework that eliminates the need for complex external alignment mechanisms. The optical system simply needs to capture images of the sample and carrier reference marks, making the entire system simpler and more robust.
3Reliability
If furnace body is sealed for vacuum and inert gas operation, then reliability is improved, but ease of manufacture and assembly worsens
Solution Approach 1:
The furnace body is divided into separable components (upper and lower parts) that can be assembled and disassembled. This segmentation allows for easier manufacturing and assembly while maintaining the sealed chamber configuration needed for vacuum and inert gas operation. The separate components can be manufactured independently and then sealed together using appropriate sealing elements.
Solution Approach 2:
Sealing elements act as intermediaries between the furnace components, enabling the formation of a sealed chamber without requiring complex integrated sealing structures. These sealing elements (such as O-rings or flange seals) provide the necessary barrier for vacuum and inert gas operation while simplifying the assembly process, as they can be installed between separate components rather than requiring monolithic sealed designs.
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 easy and precise measurement of sample length at any point on the carrier without aligning optical systems, with improved accessibility and operational modes under vacuum and inert gas, facilitating quick and accurate thermal expansion analysis.
Implementation Method 1
A light source and a collimator for generating a parallel beam path are arranged on one side of the furnace
Implementation Method 2
collimator for generating a parallel beam path
Implementation Method 3
the length of the sample can be detected via a shadow image by a sensor arranged on the opposite side
Implementation Method 4
a filter is provided on the receiver side, which is permeable only to rays of a specific wavelength that are emitted on the light source side
Implementation Method 5
A telecentric optical system is preferably arranged on the receiver side. The shadow image through the sample can then be imaged onto a sensor
Implementation Method 6
the sample carrier being arranged radially centered in the sample chamber and between an upper and a lower heating element
Implementation Method 7
For the formation of a uniform temperature profile, the sample chamber has a cylindrical shape
Data Source
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AI summary
The dilatometer has a furnace, in which a sample (11) is stored on a sample carrier (14), and an optical system for measuring a length of the sample with different temperatures. A light source (32) e.g. gallium nitrate light emitting diode, and a collimator (34) are arranged at a side of the furnace for producing parallel optical paths, and the length of the sample is detected by a shadow image by a sensor (38) e.g. charged couple sensor, that is arranged on an opposite side of the furnace. A filter is provided on a receiver side, and is permeable only for the rays of a certain wavelength.