Exhaust Gas Analyzer Vacuum Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exhaust gas analyzers face precision issues during automatic calibration due to contaminating gases in external air and insufficient gas filtering, leading to inaccurate determination of the electrical reference quantity.
Innovation Solution
The system employs an electronic control unit that performs a vacuum-based calibration by evacuating the analysis chamber to a minimum vacuum pressure, allowing for a precise determination of the electrical reference quantity, and then measures exhaust gas concentrations using infrared multidetectors and an emitter device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If automatic calibration is performed using external environmental air as reference, then the calibration process is simple and fast, but the measurement precision deteriorates due to contaminating gases in the air
Solution Approach 1:
The patent extracts the harmful contaminating gases from the reference air by introducing the reference air into the analysis chamber and measuring the electrical reference quantity, then using this measured value to compensate for the contamination effects in subsequent exhaust gas measurements
Solution Approach 2:
The patent changes the parameter being measured by the multidetector device from absolute gas concentration to differential concentration by subtracting the electrical reference quantity (measured during calibration with reference air) from the electrical quantity measured during exhaust gas analysis
2Ease of manufacture
If active-carbon filter is used to filter reference air, then the filtering process is simple, but the manufacturing precision deteriorates due to insufficient gas filtering capacity
Solution Approach 1:
The patent introduces a feedback mechanism where the electrical reference quantity measured during calibration is used to compensate for the insufficient filtering capacity of the active-carbon filter, allowing the system to account for remaining contaminating gases in subsequent measurements
Solution Approach 2:
The patent changes the approach from attempting to physically remove all contaminants through filtering to measuring and compensating for the contaminant levels through electrical reference quantity determination
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 method ensures a precise calculation of gas concentrations by establishing a reliable zero gas concentration reference, enhancing the accuracy of subsequent gas measurements.
Implementation Method 1
an infrared-emitter source designed to emit within the gas_analysis chamber a beam of radiation in the infrared frequency band; an infrared multidetector device configured for generating an electrical signal of an electrical quantity that indicates absorption of radiation by the exhaust gases in given frequency bands
Implementation Method 2
govern a pump to create, within the gas_analysis chamber, a minimum vacuum pressure corresponding substantially to a vacuum condition
Data Source
Figure 1
Figure 2
AI summary
An exhaust-gas analyser system (1) for determining the concentration of one or more exhaust gases emitted by an automotive internal-combustion engine, comprising: an infrared multidetector device (5) provided with: a gas-analysis chamber (6) structured so as to contain the exhaust gases to be analysed; an emitter source (7) configured so as to emit infrared radiation into the analysis chamber (6); infrared multidetectors (8) designed to generate electrical measurement quantities, on the basis of absorption of radiation by one or more exhaust gases; an intake pump (11) connected to the analysis chamber (6) for taking in the gases present therein; and an electronic control unit (15) that determines the concentration of one or more exhaust gases on the basis of a series of electrical measurement quantities (Vmi) supplied by the infrared multidetectors (8) and of an electrical reference quantity (V0); the electronic control unit (15) controls the intake pump (11) in such a way as to take in the residual gases contained in the analysis chamber (6) until a condition of absence of gases is reached and determines the electrical reference quantity (V0) on the basis of the electrical quantity generated by the infrared detectors (8) in the condition of absence of gases.