A5007185501- Calibration and Measurement Techniques
- Luminescence Properties of Advanced Materials
- Spectroscopy and Laser Applications
- Advanced Combustion Engine Technologies
- Combustion and flame dynamics
- Chemical Thermodynamics and Molecular Structure
- Atmospheric Ozone and Climate
- Glass properties and applications
- Radiative Heat Transfer Studies
- Optical properties and cooling technologies in crystalline materials
- High-Temperature Coating Behaviors
- Advanced Semiconductor Detectors and Materials
- Graphene research and applications
- Thermography and Photoacoustic Techniques
- Carbon Nanotubes in Composites
- Thermochemical Biomass Conversion Processes
- Advanced Sensor Technologies Research
- Diamond and Carbon-based Materials Research
- Atmospheric chemistry and aerosols
- Infrared Target Detection Methodologies
Lund University
2020-2023
Phosphor thermometry for surface temperature measurements has become an established remote technique. However, measuring at temperatures above 1700 K is still challenging because of the weak phosphorescence and intense background from black-body radiation, leading to low signal-to-noise ratios. Therefore, lifetime-based phosphor with YAG:Tm;Li YAG:Dy high-temperature applications were investigated in this study aim improving precision measurements. The phosphors coated on alumina-oxide disc,...
We report accurate in-situ optical measurements of surface temperature, volatile gas and polycyclic aromatic hydrocarbon (PAH) emission over the whole burning history individual biomass pellets in various combustion atmospheres. Two fuels, wood straw, were prepared cylindrical ∼300 mg. The burned a well-controlled atmosphere provided by laminar flame burner with temperature ranging from 1390 K to 1840 K, oxygen concentration zero 4.5%. was accurately measured, for first time, using phosphor...
Abstract This study investigates photomultiplier tube (PMT) nonlinearities, relevant for lifetime phosphor thermometry, at various decay times to assess and minimize the impact on temperature measurement accuracy. The focus is single-shot measurements performed in harsh environments where signal attenuation often a concern. sensitivity of time changing phosphorescence intensity therefore investigated. experimental results show that studied phosphors detectors, shorter between 20 ns 6 µs,...
Abstract Measuring the temperature below surface of a thermal barrier coating (TBC) using thin phosphor layer is challenging primarily due to absorption and scattering laser excitation light luminescence as they propagate through coating. One way increase could be use upconversion thermometry, which investigated in current study. It attractive because longer wavelengths reduces TBCs 8% wt. yttria-stabilize zirconia (8YSZ) generally has lower coefficients around 1000 nm than at 532 355 nm....
With high-speed phosphor thermometry becoming more established follows the need for an improved understanding of laser excitation induced measurement errors. this aim in mind, impact kHz on lifetime method was investigated phosphors Mg3FGeO6:Mn (MFG) and YVO4:Tm. The results showed that significant errors can occur both phosphors. Maximum Entropy Method (MEM) utilized to observe changes distribution decay time with fluence repetition rate. In light analysis, it concluded measured therefore...
Abstract A method is specified which enables lifetime calibration of multiple phosphors and emission lines at the same time to temperatures above 1900 K. The experimental setup algorithm used for data collection equipment control are described. were coated on an alumina oxide disc reference temperature was measured using three type B thermocouples. automates process such that no input from operator required during operation. potential systematic error in evaluated less than 1% around 1400
Phosphor thermometry is a temperature measurement technique that has previously been employed in technically relevant applications to obtain surface temperature. The based on temperature-dependent changes phosphor's luminescence. To improve the accuracy and precision of measurements with this technique, present study considers, by way example, impact conditions inside cylinder diesel engine decay time single-shot phosphor measurements. After an initial, general assessment effect prevailing...
A thermographic phosphor's decay time distribution over its temperature-sensitive range was retrieved with the Maximum Entropy Method (MEM). consists of a times, each an associated weighting for component's prevalence in analyzed curve. With MEM, significant contributions curve have high and are therefore found as peaks distribution, where width peak value correlated relative weight components. These give increased insight into lifetime behavior, which often cannot accurately be represented...
The surface temperature of a burner nozzle using three different pilot hardware configurations was measured lifetime phosphor thermometry with the ZnS:Ag in gas turbine model combustor designed to mimic Siemens DLE (Dry Low Emission) burner. included non-premixed injection setup and two partially premixed injections where one had relatively higher degree premixing. For each configuration, operated either methane or hydrogen-enriched (H2/CH4: 50/50 volume %). local heating from flames much...
Photomultiplier tube (PMT) nonlinearities relevant for single shot high-speed lifetime phosphor thermometry were investigated by simulating decay curves with a light emitting diode (LED) at repetition rates between 1 Hz and 10 kHz. The PMT gain, LED time, background radiant flux also varied to investigate their impact on the measured time error. Errors in due nonlinear performance lead temperature measurement errors; therefore, having sensitive only is highly valuable more reliable...