Chromatography Pump Pulse Noise Elimination via Comb Filter
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Solution Overview
Problem
Chromatography systems face limitations in distinguishing between chromatography peaks and pump pulses, leading to residual noise in analytical instrument signals, which affects the accuracy of viscosity measurements despite optimized pump and instrumentation designs.
Innovation Solution
An automated method involving data collection, power spectrum analysis, determination of the fundamental pump frequency, construction of a comb filter to remove noise around this frequency, and application of the filter to eliminate pump pulses from the data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chromatography systems use sophisticated computer-controlled pumps to minimize flow and pressure variations, then pump performance and flow stability are improved, but residual periodic noise (pump pulses) still appears in analytical instrument signals
Solution Approach 1:
The patent extracts and removes the harmful pump pulse noise from the analytical signal by identifying and eliminating specific frequency components through spectral analysis and filtering, while preserving the useful chromatography signal
Solution Approach 2:
The patent transforms the signal from time domain to frequency domain through Fourier transform, allowing identification and removal of periodic noise at specific frequencies while maintaining the integrity of the chromatography peaks
2Measurement precision
If automated methods are used to remove pump pulse noise, then measurement accuracy is improved, but the complexity of data processing increases
Solution Approach 1:
The system performs self-diagnosis and self-correction by automatically analyzing the power spectrum to identify pump pulse frequencies and applying appropriate filters without requiring manual intervention or complex user configuration
Solution Approach 2:
The method uses feedback from the power spectrum analysis to automatically adjust the filtering parameters, creating a closed-loop system that adapts to the specific characteristics of the pump noise in each measurement
Data Source
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AI summary
A method to filter out pump pulses from data collected with a chromatography system is disclosed. Baseline data is collected as a pump delivers solvent to an analytical instrument, which may be the IP signal of a capillary bridge viscometer. A Fourier transform is applied to the data to generate the power spectrum of the baseline signal. Fundamental and harmonic frequencies are determined and a comb filter is constructed therefrom and applied to sample collected from all of the affected instruments. The comb filter may be correlated to the pump and flow rate and stored in data analysis software or database. Other systems using other pumps may also generate associated comb filters, and the resulting filters and the flow rates at which they were generated may be stored in a database accessible to the data analysis software.