Nonlinear temperature calibration equation for Rhodamine B in different solutions for wide-temperature-range...

Area of Science:

• * Spectroscopy
• * Physical Chemistry
• * Chemical Engineering

Background:

• * Accurate temperature measurement is crucial for quantitative analysis in various applications.
• * Two-color laser-induced fluorescence (LIF) ratio thermometry is a valuable technique for temperature determination.
• * Rhodamine B is a common fluorescent dye used in thermometry, but its temperature behavior needs precise calibration.

Purpose of the Study:

• * To investigate the temperature-dependent spectral behavior of Rhodamine B in aqueous and ethanol solutions.
• * To develop an accurate calibration method for two-color LIF thermometry over a wide temperature range (-30°C to 90°C).
• * To compare the performance of a nonlinear fitting method with traditional linear models.

Main Methods:

• * Spectroscopic analysis of Rhodamine B in aqueous and ethanol solutions.
• * Two-color laser-induced fluorescence (LIF) ratio measurements.
• * Nonlinear fitting of spectral data using an Arrhenius equation-based model.

Main Results:

• * Demonstrated the nonlinear temperature behavior of Rhodamine B.
• * Developed a nonlinear calibration equation that improves temperature measurement accuracy by 2°C-3°C compared to linear models.
• * Achieved higher temperature sensitivity at lower temperatures, indicating suitability for low-temperature applications.

Conclusions:

• * The nonlinear fitting method based on the Arrhenius equation provides a more accurate calibration for Rhodamine B in LIF thermometry.
• * This approach enhances temperature measurement accuracy and sensitivity, particularly in wide temperature ranges and low-temperature environments.
• * The study validates the feasibility of this method for precise temperature determination in demanding applications.