Vacuum Pressure Sensing with Plasma Emission Ratio Detection
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Solution Overview
Problem
Existing vacuum pressure sensors face limitations in their measurable pressure range due to ambiguity in current measurements caused by changes in plasma composition at higher pressures, restricting their usable range beyond a certain current intensity maximum.
Innovation Solution
A method involving the generation of plasma in a sample chamber connected to the vacuum system, measuring current intensity and radiation intensities at specific wavelengths to determine pressure, allowing for extended range measurements by resolving ambiguity through additional radiation intensity data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional current measurement methods are used in vacuum pressure sensors, then the device complexity remains low, but the measurement precision deteriorates due to ambiguity in the pressure-current calibration curve at higher pressures
Solution Approach 1:
The patent introduces radiation intensity measurements as an intermediary parameter to resolve the ambiguity in pressure determination. By measuring radiation intensity at two different wavelength ranges and using their ratio, the system obtains additional independent information that acts as a mediator to uniquely identify pressure values, eliminating the ambiguity present in conventional single-parameter current measurement methods.
Solution Approach 2:
The patent transitions from one-dimensional pressure measurement (using only current intensity) to two-dimensional measurement by adding radiation intensity ratio as a second independent parameter. This dimensional expansion allows the system to resolve the non-monotonic behavior of the pressure-current calibration curve, enabling unambiguous pressure determination across a wider pressure range.
2Adaptability or versatility
If the pressure measurement range is extended beyond the current intensity maximum, then the productivity of pressure monitoring is improved, but the measurement precision deteriorates due to plasma dominance and current decrease with increasing pressure
Solution Approach 1:
The patent changes the measurement parameters from relying solely on current intensity to using the ratio of radiation intensities at two different wavelength ranges. This parameter transformation allows the system to maintain measurement precision in the pressure range above the current maximum, where conventional current-based methods fail due to the non-monotonic relationship between current and pressure.
3Measurement precision
If radiation intensity measurements at multiple wavelengths are added to resolve measurement ambiguity, then the measurement precision is improved, but the device complexity increases due to additional measurement components
Solution Approach 1:
The patent designs the sensor to perform multiple functions using integrated components. The same plasma generation mechanism simultaneously produces both the current signal and the radiation signals, and the detector system is configured to measure multiple wavelength ranges. This multi-functionality approach allows the system to obtain multiple measurement parameters without proportionally increasing device complexity.
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 precise determination of vacuum pressure over a wider range by using plasma-generated radiation intensity ratios, enhancing the accuracy and unambiguity of pressure measurements beyond conventional limits.
Implementation Method 1
measuring a first radiation intensity of electromagnetic radiation of a first wavelength range which is emitted from the plasma, wherein the first wavelength range contains at least a first emission line of a first plasma species of a first chemical element
Implementation Method 2
measuring a current intensity of an electrical current flowing through the plasma between the first electrode and the second electrode
Data Source
AI summary
The invention relates to a method 100 for determining a pressure in a vacuum system, wherein the method comprises the steps of:a) generating 101 a plasma in a sample chamber which is fluid-dynamically connected to the vacuum system and which is in electrical contact with a first electrode and a second electrode;b) measuring 102 a current intensity of an electrical current flowing through the plasma between the first electrode and the second electrode;c) measuring 103 a first radiation intensity of electromagnetic radiation of a first wavelength range which is emitted from the plasma, wherein the first wavelength range contains at least a first emission line of a first plasma species of a first chemical element;d) measuring 104 a second radiation intensity of electromagnetic radiation of a second wavelength range which is emitted from the plasma, wherein the second wavelength range contains a second emission line of the first plasma species of the first chemical element or of a second plasma species of the first chemical element, and wherein the second emission line is outside the first wavelength range; ande) determining 105 the pressure in the vacuum system as a function of the measured current intensity, the measured first radiation intensity, and the measured second radiation intensity. Further, the invention relates to a vacuum pressure sensor.