Integrated Valve Terminal for High-Precision Seawater pH Measurement
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Solution Overview
Problem
Current seawater pH measurement systems face challenges with large volume and high power consumption, limited resolution, and accuracy due to their flow path and light source configurations, which restrict the measurement of multiple indicators and precision.
Innovation Solution
A high-precision seawater pH in-situ measurement system based on an integrated valve terminal with a compact flow path structure and LED-coupled light source using a miniature spectrometer, enabling the measurement of multiple indicators and improving accuracy and range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a three-way valve combination or multi-position valve is used in the flow path, then the system can control fluid flow, but the system volume increases and power consumption increases
Solution Approach 1:
The patent integrates multiple valve functions into a single integrated valve terminal, combining what would traditionally be separate three-way valves or multi-position valves into one compact unit. This merging reduces the overall system volume while maintaining the necessary flow control capabilities for the photometric pH measurement system.
Solution Approach 2:
The integrated valve terminal is designed to perform multiple flow control functions simultaneously, serving as a universal control component that replaces several specialized valves. This multi-functionality approach reduces the number of components needed, thereby decreasing system volume and power consumption while maintaining operational ease.
2Device complexity
If LED and photodiode combination is used for light source and detection, then the system is simple, but measurement resolution and accuracy are poor
Solution Approach 1:
The patent replaces the simple LED-photodiode optical system with a more advanced photometric detection system that uses a microspectrometer. This substitution improves measurement resolution and accuracy by enabling precise wavelength-specific absorbance measurements, while the system remains relatively compact through the use of miniaturized optical components.
Solution Approach 2:
The system transitions from broadband LED detection to wavelength-resolved spectrometric detection, changing the detection parameter from simple intensity measurement to spectral absorbance measurement. This parameter change enables more precise pH determination through flow injection analysis while maintaining practical system complexity through integrated design.
3Volume of stationary object
If a compact flow path structure is used, then system volume decreases, but measurement stability may be affected
Solution Approach 1:
The patent employs a nested flow path design where components are arranged concentrically or in layered configurations within the integrated valve terminal. This nesting approach maximizes the use of internal space, achieving compact system volume while maintaining adequate flow paths for stable mixing and measurement of seawater samples with indicators.
Solution Approach 2:
The compact flow path is segmented into distinct functional zones within the integrated terminal, separating sample introduction, indicator mixing, and detection regions. This segmentation allows each zone to be optimized for its specific function, maintaining measurement stability despite the reduced overall volume.
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 system achieves stable, low-power, and high-precision pH measurements across a broader range by utilizing a compact valve terminal and LED-coupled light source with a miniature spectrometer, allowing for the detection of multiple indicators and enhancing measurement stability and accuracy.
Implementation Method 1
the optical path module is used to measure absorbance of sample at characteristic wavelengths
Implementation Method 2
the photometric method is integrated with a flow injection analysis technology in which seawater pH could be obtained by measuring absorbance of indicators in varied forms
Data Source
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AI summary
High-precision Seawater pH in-situ Measurement System and Method based on Integrated Valve-terminal Apparatus The present invention belongs to the technical field of marine monitoring, and specifically relates to a high-precision seawater pH in-situ measurement system and method based on an integrated valve-terminal apparatus capable of testing multiple reagents. The measurement system comprises a flow path module, an optical path module, and a circuit module; the flow path module comprises an integrated valve terminal which controls the direction of the flow path, said flow path module being used for performing seawater sample injection, reagent sample injection, and mixing; the flow path is controlled by means of the integrated valve terminal; when measuring the seawater pH in situ, first, seawater is injected into the flow path to determine the blank light intensity; then an indicator is injected into the flow path, the flow path is closed into a loop, and seawater and the indicator are mixed in the loop; after mixing is complete, the light intensity of the mixed solution is measured, the absorbance is calculated, and thus the seawater pH is calculated. A valve terminal apparatus is used as the flow path structure of the present invention, and has the features of small dead volume, compact structure, and low power consumption, and is capable of achieving complete mixing of seawater and indicator, improving the stability of instrument measurement.