Miniaturized Pressure Gauge with Segmented Strain Gauge Surfaces
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Solution Overview
Problem
Conventional pressure gauges in HPLC, SFC, and SFE systems have inadequate solvent exchange, leading to fluid stagnation and contamination of samples, and are difficult to miniaturize without compromising measurement precision.
Innovation Solution
A pressure gauge with a metallic body featuring a straight cylindrical internal space and strategically placed strain-measurement and temperature-correction surfaces allows for improved solvent exchange and measurement precision by attaching strain gauges to specific areas, reducing internal capacity while maintaining effective pressure detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pressure gauges are used in HPLC, SFC, and SFE systems, then pressure measurement is possible, but solvent exchange is inadequate leading to fluid stagnation and sample contamination
Solution Approach 1:
The pressure gauge body is divided into distinct functional regions: a first region with reduced wall thickness for pressure detection and a second region with normal wall thickness for structural support. This segmentation allows the pressure-sensitive area to be minimized while maintaining overall structural integrity, thereby improving solvent exchange without compromising measurement capability.
Solution Approach 2:
The pressure gauge features non-uniform wall thickness distribution, with the first region having reduced thickness specifically where pressure measurement is needed. This local quality change enables effective pressure detection while minimizing the volume that could cause fluid stagnation, directly addressing the solvent exchange problem.
2Reliability
If pressure gauge internal capacity is reduced to improve solvent exchange, then measurement precision may be compromised
Solution Approach 1:
The pressure gauge employs localized thin-walled construction in the first region specifically for pressure detection, while the second region maintains normal wall thickness for structural support. This allows the internal capacity to be reduced in the pressure-sensitive zone to improve solvent exchange, while the overall structure remains robust enough to maintain measurement precision.
Solution Approach 2:
By segmenting the pressure gauge body into two regions with different wall thickness characteristics, the design achieves both improved solvent exchange in the first region and structural integrity in the second region, resolving the contradiction between reduced internal capacity and measurement precision.
3Productivity
If conventional pressure gauge design is used, then pressure measurement is possible, but device miniaturization is difficult
Solution Approach 1:
The pressure gauge body is segmented into a first region with reduced wall thickness for pressure sensing and a second region for structural support. This segmentation enables miniaturization of the overall device while preserving measurement precision, as the critical pressure detection function is concentrated in the optimized first region rather than requiring uniform thick walls throughout.
Solution Approach 2:
The non-uniform wall thickness distribution with localized thin-walled first region allows the pressure gauge to be miniaturized while maintaining pressure detection capability. The reduced thickness in the pressure-sensitive zone enables smaller overall dimensions without sacrificing measurement precision.
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
The solution provides enhanced solvent exchange, reduced internal capacity, and improved measurement precision, enabling accurate pressure monitoring with higher response and lower production costs, suitable for use in pumps and back pressure regulators.
Implementation Method 1
measuring a strain produced when pressure is applied to a metallic pressure gauge body
Implementation Method 2
a strain gauge for outputting the strain of a thin diaphragm formed at a tip of the housing as an electrical signal
Implementation Method 3
temperature-correction surfaces allows for improved solvent exchange and measurement precision by attaching strain gauges to specific areas
Data Source
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AI summary
A pressure gauge mounted to a pump or a back pressure regulator in an HPLC, SFC, or SFE system provides improved solvent exchange and improved measurement precision. A through hole having an inside diameter of 1.0 mm is made in a hexagonal member similar in shape to a pipe joint. A part of the hexagonal member is cut away to form a flat surface such that the distance to the outside periphery of the through hole is 0.5 mm to serve as a strain-measurement strain gauge attaching surface. One strain gauge is attached to the center of the strain-measurement strain gauge attaching surface, and two strain gauges are attached for temperature correction, one on the same surface as the strain-measurement strain gauge attaching surface and the other on an outside surface of the hexagonal member.