Infrared Thermometer Calibration Using Emissivity Correction Factors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Infrared thermometers face calibration inaccuracies due to temperature-dependent emissivity variations, which are not accounted for by their constant emissivity settings, leading to incomplete temperature range calibration.
Innovation Solution
A calibration system that uses a thermal target with temperature-dependent emissivity and a reference IR thermometer to calculate correction factors, allowing the IR thermometer to accurately map measured radiation to temperatures, ensuring calibration across a range of temperatures by equating radiation to that of a graybody with the same emissivity setting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a thermal target with temperature-dependent emissivity is used for calibration, then calibration accuracy across a temperature range is improved, but the device complexity increases due to the need for correction factors and reference measurements
Solution Approach 1:
A reference IR thermometer is introduced as an intermediary device to measure the radiance from the thermal target. This reference instrument, with known calibration, serves as a mediator to determine correction factors that account for the target's temperature-dependent emissivity, enabling accurate calibration of the test IR thermometer without requiring direct knowledge of the target's varying emissivity characteristics
Solution Approach 2:
The system performs calibration at multiple temperature set points rather than a single temperature. By changing the temperature parameter and measuring radiance at each point, correction factors are calculated to map between set point temperatures and apparent temperatures, accounting for the target's emissivity variations across the temperature range
2Ease of operation
If a constant emissivity setting is used in the IR thermometer, then the device operation is simplified, but calibration accuracy deteriorates when measuring bodies with different emissivities across temperature ranges
Solution Approach 1:
The system performs preliminary calibration measurements at multiple temperature set points using a reference IR thermometer to calculate correction factors before actual temperature measurements are taken. These pre-calculated correction factors, stored in memory, compensate for emissivity variations, allowing the IR thermometer to maintain a simple constant emissivity setting while achieving accurate measurements across different temperatures and emissivity values
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 provides accurate calibration of IR thermometers across a range of temperatures by accounting for emissivity variations, ensuring precise temperature measurements by adjusting for emissivity differences, thereby enhancing the accuracy and reliability of temperature readings.
Implementation Method 1
Infrared (IR) thermometers measure the IR radiation from bodies and output a temperature corresponding to the intensity of radiation measured within the frequency range of the IR thermometer
Implementation Method 2
a reference IR thermometer to calculate correction factors, allowing the IR thermometer to accurately map measured radiation to temperatures
Data Source
AI summary
Infrared IR thermometer calibration systems and methods are disclosed in which the temperature of an IR thermometer calibration system is controlled such that radiation emitted by a target at a given input temperature is equal to the radiation emitted by a graybody heated to the input temperature and having an emissivity equal to an emissivity setting of an IR thermometer to be calibrated using the IR thermometer calibration system.