PDF Publication Title:
Text from PDF Page: 390
Lanthanides in Luminescent Thermometry Chapter 281 355 I2 ! 0, since the thermometer readout reaches the system-operating limit, ie, a bound value defined in accordance with a reliability criterion (Robertson and Lee, 2002). In this case, a reasonable operating approach must consider as reliable intensity values only those that are 5% higher than the noise level (or baseline), thus ensuring the adequate consistency of the thermometer read- out within the system-operating limit. This operational criterion is quite gen- eral, independently of the adopted form for D. Although in the limit I2!0 Eqs. (2) and (3) keep their physical meaning, variations in D lower than its intrinsic error (corresponding to negligible changes on I1 and I2) means that the system-operating limit is reached. 3.1 Relative Thermal Sensitivity The relative thermal sensitivity Sr indicates the relative change of D per degree of temperature change and is defined by: S 1⁄4 1 @D (4) r D@T This parameter (usually expressed in units of % change per Kelvin of tem- perature change, %K1) was defined in 2003 in the context of optical fiber point temperature sensing (Wade et al., 2003) and since our initial purpose in 2012 (Brites et al., 2012), has been commonly used as a figure of merit to compare different thermometers, independently of their nature (Benayas et al., 2015; Carrasco et al., 2015; Cero ́n et al., 2015; Cui et al., 2015b; McLaurin et al., 2013; Wang et al., 2015c; Zhou et al., 2014d). The maximum value of Sr is denoted as Sm. We note that Sr>0 (negative sensitivities make no sense) and a negative signal in @D/@T means that D decreases as tempera- ture increases. Compared to the absolute sensitivity (dos Santos et al., 1998), Sa 1⁄4@D (5) @T Sr presents the critical advantage to be independent of the nature of the ther- mometer (ie, mechanical, electrical, optical) allowing direct and quantitative comparison between different samples, a powerful tool when different techni- ques are considered. Although frequently seen in the literature, Sa cannot be used to compare the performance of distinct luminescent thermometers as it depends on the sample characteristics (eg, absorption and lifetimes) and on the experimental setup. 3.2 Temperature Uncertainty The temperature uncertainty (or temperature resolution) dT is the smallest temperature change that can be detected in a given measurement. Assuming that the temperature uncertainty of a thermometer results only fromPDF Image | HANDBOOK ON THE PHYSICS AND CHEMISTRY OF RARE EARTHS
PDF Search Title:
HANDBOOK ON THE PHYSICS AND CHEMISTRY OF RARE EARTHSOriginal File Name Searched:
Chemistry-Rare-Earths-49.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |