Tunable Laser Gas Analyzer Vibration Resilience

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional laser gas analyzers using tunable diode laser absorption spectroscopy (TDLAS) face issues with data collection due to vibrations, particularly when the frequency of the vibration source coincides with the natural frequency of the probe, leading to resonance and incomplete scanning signals, which prevents accurate measurement of gas density.

Innovation Solution

A spectroscopic analysis apparatus equipped with an acceleration sensor that detects probe vibrations, allowing the controller to adjust the scanning time to be equal to or shorter than half the light-receivable time, ensuring complete scanning signals are obtained despite vibrations, and incorporates noise suppression through signal integration and averaging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the laser gas analyzer is mounted on the flue wall for stable installation, then the device structure is simplified and ease of operation is improved, but vibration from nearby devices (motors, fans) causes resonance when vibration frequency matches the natural frequency of the probe, leading to violent vibration and measurement failure

Engineering Contradiction:
Improveinstallation convenienceVSAvoidmeasurement reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies dynamics by making the scanning time adjustable and adaptive rather than fixed. The system dynamically adjusts the scanning time based on detected vibration conditions, allowing it to adapt to changing environmental vibrations while maintaining stable installation on the flue wall. This resolves the contradiction by enabling the system to remain reliable under varying vibration conditions without requiring complex isolation structures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of scanning time from a fixed value to a variable that can be adjusted based on vibration detection. By monitoring vibration frequency and amplitude, the system modifies the scanning time parameter to ensure complete scanning signals are acquired even during resonant conditions, thereby maintaining measurement reliability while keeping the installation simple.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the scanning time is extended to ensure complete scanning signals are acquired during vibration, then measurement accuracy is improved, but productivity decreases due to longer measurement cycles

Engineering Contradiction:
Improvescanning signal completenessVSAvoidmeasurement speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system dynamically adjusts scanning time based on real-time vibration detection rather than using a fixed extended scanning time. When vibration is detected, the scanning time is increased to ensure complete signals. When no vibration is present, the scanning time returns to normal duration, maintaining high productivity. This dynamic adaptation resolves the contradiction between measurement precision and productivity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by using vibration sensors to detect vibration conditions and then adjusting the scanning time accordingly. The system continuously monitors vibration frequency and amplitude, and based on this feedback, modifies the scanning time to ensure complete scanning signals are acquired only when necessary, thereby maintaining both measurement precision and productivity.

Inventive Principle:
Principle #23Feedback

3Reliability

If vibration damping structures are added to reduce probe vibration, then measurement reliability is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvemeasurement stabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical vibration damping structures with a control system that uses sensors to detect vibration and adjusts the scanning time parameter accordingly. Instead of adding mechanical dampers or isolation structures, the system uses electronic control to adapt the scanning process to vibration conditions, thereby maintaining measurement reliability without increasing structural complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

Rather than modifying the physical structure to reduce vibration, the patent changes the operational parameter of scanning time to compensate for vibration effects. By adjusting the scanning time based on detected vibration conditions, the system ensures complete scanning signals are acquired without needing complex mechanical damping structures, thus maintaining simplicity while improving reliability.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If the laser scanning speed is increased to maintain productivity, then measurement speed is improved, but the likelihood of acquiring incomplete scanning signals during vibration increases, reducing measurement precision

Engineering Contradiction:
Improvescanning speedVSAvoidsignal completeness
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system dynamically adjusts the scanning speed (inverse of scanning time) based on vibration detection. During normal conditions, the laser scans at high speed to maintain productivity. When vibration is detected, the scanning time is extended to ensure complete signals are acquired. This dynamic adjustment resolves the contradiction between productivity and measurement precision.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses vibration sensor feedback to control the scanning speed. When vibration frequency and amplitude exceed thresholds, the system slows down the scanning speed by extending the scanning time to ensure complete signal acquisition. When vibration is absent, the system maintains high scanning speed for productivity. This feedback-based control resolves the contradiction between scanning speed and signal completeness.

Inventive Principle:
Principle #23Feedback

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 reliable measurement of gas density even under resonant conditions by ensuring complete scanning signals are acquired and noise is minimized, thereby maintaining measurement accuracy.

Implementation Method 1

measures the intensity of the absorption spectrum

Methodology Applied
Scientific EffectAbsorption spectroscopy: Absorption Spectroscopy

Implementation Method 2

absorbance is in proportion to a component density and the length of an optical path (Lambert Beer's law)

Methodology Applied
Scientific EffectLambert Beer's law:

Implementation Method 3

an acceleration sensor that detects an acceleration of a vibration of the probe

Methodology Applied
Scientific EffectVibration detection: Vibration

Implementation Method 4

incorporates noise suppression through signal integration and averaging

Methodology Applied
Scientific EffectSignal integration and averaging:

Data Source

PatentEP3527970B1Spectroscopic analysis apparatus
Publication Date: 2021.04.07 YOKOGAWA ELECTRIC CORP
  • EP3527970B1 patent drawingFigure 1
  • EP3527970B1 patent drawingFigure 2
  • EP3527970B1 patent drawingFigure 3

AI summary

A spectroscopic analysis apparatus includes a laser light source (20) that emits laser light (L1), of which wavelength changes, toward a reflector (12) inside a probe (1), the probe (1) being configured to be disposed in a flow passage of a measurement target fluid, a light receiver (21) that receives the laser light reflected by the reflector (12), and a controller (22) that analyzes the measurement target fluid using a result of reception acquired by the light receiver (21) and controlling the laser light source (20). The controller (22) controls the laser light source (20) to perform at least one scan of the laser light, the controller (22) controlling the laser light source (20) such that a scanning time of the laser light is equal to or shorter than a light-receivable time, the scanning time being a time to scan the laser light emitted from the laser light source in a certain wavelength range, the light-receivable time being a time in which the laser light reflected by the reflector (12) can be received by the light receiver (21).