Flow Rate Calibration Using Adaptive Error Ranges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Calibrated flow rate control devices in gas supply systems for semiconductor manufacturing face inaccuracies due to variations in reference volume caused by piping design and manufacturing tolerances, leading to errors in flow rate measurements.
Innovation Solution
A method of calibrating flow rate control devices by setting a smaller permissible error range for specific flow rate settings and using a flow rate measuring device with a pressure and temperature sensor to measure the reference volume, allowing for accurate flow rate measurements with reduced calibration time and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If flow rate control devices are calibrated to predetermined accuracy using standard permissible error ranges, then calibration time and cost are reduced, but measurement precision deteriorates due to accumulated errors in reference volume calculation
Solution Approach 1:
The patent changes the parameter of permissible error range from a fixed standard value to a variable value that adapts to each flow rate setting. By dynamically adjusting the permissible error range based on the specific flow rate being measured, the system achieves high measurement precision without requiring excessive calibration time, as the error tolerance is optimized for each operating condition rather than using a conservative fixed value throughout
Solution Approach 2:
The patent introduces dynamics into the calibration process by making the permissible error range adaptive rather than static. The calibration system dynamically determines appropriate error ranges based on flow rate settings, allowing the measurement system to maintain high precision across varying operating conditions while minimizing calibration time through intelligent error tolerance management
2Measurement precision
If flow rate control devices are repeatedly calibrated to reduce error, then measurement precision improves, but calibration time and cost increase
Solution Approach 1:
The patent changes the permissible error range parameter to be setting-dependent, allowing each flow rate setting to have its own optimized error tolerance. This eliminates the need for repeated calibrations across all settings, as each setting is calibrated once with an appropriately tailored error range that balances precision requirements with calibration efficiency
Solution Approach 2:
The patent applies partial calibration action by calibrating each flow rate setting to its specific permissible error range rather than applying uniform over-calibration to all settings. This partial approach focuses calibration resources where needed, achieving sufficient precision without the excessive time and cost of repeated comprehensive calibrations
3Ease of manufacture
If standard permissible error ranges are used for all flow rate settings, then calibration process is simplified, but measurement precision deteriorates due to reference volume errors
Solution Approach 1:
The patent changes the permissible error range from a fixed standard parameter to a variable parameter that changes with each flow rate setting. This maintains calibration process simplicity through automated determination of error ranges while improving measurement precision by tailoring error tolerance to the specific measurement conditions, avoiding the one-size-fits-all limitation of standard ranges
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 enables accurate and efficient flow rate measurements by minimizing errors in the reference volume calculation, thereby improving the precision of flow rate control in gas supply systems.
Implementation Method 1
measuring the rate of pressure rise (ΔP/Δt)
Implementation Method 2
measuring the rate of pressure rise (ΔP/Δt) and the temperature (T) at that time
Data Source
AI summary
In a method of calibrating a flow rate control device in which a flow rate is calibrated based on comparison with a flow rate measured by a flow rate reference gauge, a predetermined permissible error range is set for a plurality of flow rate settings, and the permissible error range of at least one specific flow rate setting among the plurality of flow rate settings is set to be smaller than the predetermined permissible error range.