Infrared Sensor Oscillating Temperature for Emissivity Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional non-contact temperature measurement techniques are inadequate for targets with unknown emissivity, as they often result in increased measurement uncertainty and require assumptions about emissivity, which can be incorrect, and may not be feasible in all applications, especially during manufacturing processes where emissivity can change.
Innovation Solution
The use of two sensors or a single sensor oscillating between different temperatures to measure net heat fluxes, allowing for accurate temperature and emissivity determination independent of the target's emissivity, with the ability to handle changing emissivity conditions and contamination, and without the need to zero temperature differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional infrared radiation sensors are used to measure target temperature, then temperature measurement can be performed, but measurement accuracy deteriorates when target emissivity is unknown
Solution Approach 1:
The patent changes the temperature parameter of the sensor itself, operating the sensor at multiple different temperatures to obtain multiple heat flux measurements. This allows the system to solve for both target temperature and emissivity simultaneously, resolving the accuracy issue when emissivity is unknown
Solution Approach 2:
The sensor temperature is made dynamic rather than static, oscillating between different temperatures during measurement. This dynamic operation enables the system to capture multiple data points needed to eliminate emissivity uncertainty from the temperature calculation
2Ease of operation
If assumed emissivity values are used for measurement, then temperature measurement can proceed, but measurement uncertainty increases
Solution Approach 1:
The system performs self-calibration by using its own multiple temperature measurements to automatically determine the correct emissivity value for the target. No external emissivity data or manual input is needed, and the system self-corrects for emissivity effects through mathematical analysis of the multiple heat flux measurements
3Device complexity
If sensor temperature is kept constant, then system operation is simplified, but ability to measure targets with changing emissivity is lost
Solution Approach 1:
The sensor temperature is made dynamic, oscillating between predetermined temperature values during the measurement process. This dynamic temperature variation enables the system to track and accurately measure targets whose emissivity changes over time, while the automated oscillation pattern keeps the control logic relatively simple
4Measurement precision
If zeroing temperature difference between target and sensor is performed, then measurement of unknown emissivity targets is possible, but the approach may not always be desirable or possible
Solution Approach 1:
Instead of requiring the sensor temperature to match the target temperature (zeroing approach), the patent dynamically varies the sensor temperature to multiple different values. This eliminates the need for temperature matching while still enabling accurate measurement of targets with unknown or changing emissivity, greatly expanding applicability
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 provides accurate temperature measurement and emissivity determination for targets with unknown or changing emissivity, reducing measurement uncertainty and system costs, while being insensitive to contamination and radiation from background sources.
Implementation Method 1
infrared radiation sensors determine temperature of a viewed target based on measured heat flux from the target
Implementation Method 2
measured heat flux from the target
Data Source
AI summary
Devices and corresponding methods can be provided to measure temperature and/or emissivity of a target. Emissivity of the target need not be known or assumed, and any temperature difference between a sensor and the target need not be zeroed or minimized. No particular bandpass filter is required. Devices can include one or two sensors viewing the same target as the target views different respective viewed temperatures. The respective viewed temperatures can be sensor temperatures, and a single sensor can be set to each of the respective viewed temperatures at different times. An analyzer can determine the temperature and/or emissivity of the target based on the respective viewed temperatures and on plural net heat fluxes detected by the sensors and corresponding to the respective viewed temperatures.