Gamma Density Measurement Crosstalk Reduction

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Solution Overview

Problem

Crosstalk between gamma ray emitters and detectors in round separator geometries leads to significant errors in determining density profiles, as existing calibration methods are insufficient in eliminating this issue, especially due to varying liquid levels affecting the proportion of crosstalk.

Innovation Solution

A method and device that utilize gamma energy-sensitive detectors to measure count rates only from gamma rays with energies above a Compton energy threshold, ensuring that only unscattered or minimally scattered rays are considered, thereby reducing crosstalk and improving measurement precision by focusing on gamma rays that have not significantly interacted with multiple layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If collimators are used to reduce crosstalk between emitters and detectors, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improvedensity profile determination accuracyVSAvoidcollimator structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the energy parameter threshold for accepting gamma ray signals. By setting an energy threshold that excludes scattered gamma rays (which have lower energy due to Compton scattering), the method achieves better measurement precision without adding physical collimators. This parameter-based filtering resolves the contradiction by achieving the same effect as collimators through signal processing rather than structural modification.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If all detected gamma rays are used for measurement, then counting rate increases, but measurement precision decreases due to crosstalk from scattered rays

Engineering Contradiction:
Improvecounting rateVSAvoiddensity measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent extracts and excludes scattered gamma rays from the measurement process by applying an energy threshold. Only gamma rays with energy above the threshold (unscattered or minimally scattered rays) are used for density calculation. This extraction of harmful scattered rays resolves the contradiction by maintaining high counting rates from valid signals while eliminating precision-degrading scattered signals.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If calibration is performed to improve measurement accuracy, then density determination precision improves, but crosstalk errors persist due to varying liquid levels

Engineering Contradiction:
Improvedensity determination accuracyVSAvoidcrosstalk consistency
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the selection criterion for gamma rays from a fixed calibration-based approach to an energy-based dynamic filter. By using energy threshold that adapts to exclude scattered rays regardless of liquid level, the system achieves both precision and reliability. This resolves the contradiction by making the measurement independent of varying calibration conditions caused by different liquid levels.

Inventive Principle:
Principle #35Parameter changes

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

This approach enhances the accuracy of density profile determination by filtering out scattered gamma rays and ensuring that only relevant, unscattered rays contribute to the measurement, thereby improving the precision and reliability of density measurements in multi-layered substances.

Implementation Method 1

detection of respective gamma rays which have each at least partially penetrated at least one of the substances

Methodology Applied
Scientific EffectGamma ray penetration: Absorption (EM radiation)

Implementation Method 2

gamma energy, in particular their respective gamma energy value, is equal to or greater than an energy threshold value, in particular and not less, wherein the energy threshold value is at least 0.5 times a Compton energy value of a Compton gap

Methodology Applied
Scientific EffectCompton scattering: Compton Scattering

Data Source

PatentEP3922986B1Method for measuring counting rates or measured values dependent on the counting rates, and device for measuring counting rates or measurement variables dependent on the counting rates
Publication Date: 2024.07.24 BERTHOLD TECH
  • EP3922986B1 patent drawingFigure 1~2
  • EP3922986B1 patent drawingFigure 3~4
  • EP3922986B1 patent drawingFigure 5

AI summary

The invention relates to a method for measuring count rates (ZR1, ZR2, ZR3, ZR4) or count rate-dependent measurands for determining a density profile (DP) of at least two substances (ST) with different densities (DE) arranged within a container (20) by means of a plurality of detectors (41, 42, 43, 44), wherein the method comprises the steps of: a) detecting respective gamma rays (GR) which have at least partially penetrated at least one of the substances (ST) by means of the detectors (41, 42, 43, 44), and b) generating a respective count rate (ZR1, ZR2, ZR3, ZR4) or a respective count rate-dependent measurand only based on the respective detected gamma rays (GR) whose respective gamma energy (GE) is equal to or greater than an energy threshold (ETh2), wherein the energy threshold (ETh2) is at least 0.5 times a Compton energy value (CE) of a Compton gap (CG) of the gamma rays (GR).