Search results for "temperature measurement."
showing 10 items of 120 documents
Coulomb blockade thermometer: Tests and instrumentation
1998
Coulomb blockade thermometry (CBT) provides a simple method for absolute thermometry in every day laboratory use at cryogenic temperatures. CBT has been found insensitive to even high magnetic fields. We review the principles and the operation of CBT and the fabrication of the sensors, and present new data on radiation hardness and stability of the sensors. We describe the instrumentation of CBT in detail. We have developed two signal conditioning units for CBT measurements. One is a modified alternating current resistance bridge, a versatile laboratory instrument operating with a PC computer, and the other one is a simple stand-alone instrument for direct temperature reading. Test results …
Outdoor Mean Radiant Temperature Estimation: Is the Black-Globe Thermometer Method a Feasible Course of Action?
2018
Urban planning has become one of the crucial action in order to address and mitigate the effect and the consequences of the global warming and it also entails different sectors of the urban context. The survey and control of the outdoor climatic conditions are among the involved sectors and mean radiant temperature is amid the most analyzed parameters. The aim of the paper is to investigate the effective suitability of one of the most used method in the assessment of the mean radiant temperature, namely the globe-thermometer method, in outdoor urban environment, singling out possible shortcomings and actual efficacy. Specifically, data obtained by measurement campaigns performed by means of…
Accuracy and stability of temperature probes for intracranial application.
2004
Intracranial temperature measurement may play a pivotal role for prognosis and treatment of neurological and neurosurgical patients. For reliable clinical application, accurate temperature readings are therefore necessary. We present an independent in vitro study investigating the accuracy and stability of three temperature probes. Eight Neurovent-P Temp (RN), eight Licox temperature sensors (LT) and eight Neurotrend sensors (NT) were placed into a water bath. The temperature was increased in 3 degrees C increments from 30 to 42 degrees C before (accuracy test day 0) and after (accuracy test day 5) a long-term stability test run at 37 +/- 0.2 degrees C. The accuracy tests revealed deviation…
Estimating the difference between brightness and surface temperatures for a vegetal canopy
1995
Abstract The difference between the surface temperature T S and the brightness temperature T b , which can be measured with a thermal infrared radiometer, has been calculated for different surface emissivity values and different atmospheric conditions. These calculations show that T s − T b is often significant even for high surface emissivities and that the spectral band in which the measurements are performed is a key factor in the interpretation of T s − T b . In particular, it is not a simple matter to use the characterisation of the whole spectrum atmospheric radiation to derive T s from T b when the measurements are performed in the 8–14 μm atmospheric window.
Aircraft type-specific errors in AMDAR weather reports from commercial aircraft
2008
AMDAR (Aircraft Meteorological DAta Relay) automated weather reports from commercial aircraft provide an increasing amount of input data for numerical weather prediction models. Previous studies have investigated the quality of AMDAR data. Few of these studies, however, have revealed indications of systematic errors dependent upon the aircraft type. Since different airlines use different algorithms to generate AMDAR reports, it has remained unclear whether a dependency on the aircraft type is caused by physical properties of the aircraft or by different data processing algorithms. In the present study, a special AMDAR dataset was used to investigate the physical type-dependent errors of AMD…
The infrared thermography control of the laser welding of amorphous polymers
2008
In laser welding technique, a real-time control of temperature distribution inside the irradiated materials is essential when attempting to optimize the process. For all laser welding methods that operate by the transmission principle, the difficulty of recording the developed temperature at the interface derives from the fact that materials to be welded are in contact throughout the entire process. In the present study, in order to overcome this issue, a contact-free method such the infrared thermography is used for surface temperature measurement. Corroborating this data with a numerical simulation of the temperature field evolution inside the components, an assessment of optimal process …
Radiation tolerant fiber Bragg gratings for high temperature monitoring at MGy dose levels
2014
International audience; We report a method for fabricating fiber Bragg gratings (FBG) resistant to very severe environments mixing high radiation doses (up to 3 MGy) and high temperatures (up to 230 degrees C). Such FBGs have been written in two types of radiation resistant optical fibers (pure-silica and fluorine-doped cores) by exposures to a 800 nm femtosecond IR laser at power exceeding 500 mW and then subjected to a thermal annealing treatment of 15 min at 750 degrees C. Under radiation, our study reveals that the radiation induced Bragg wavelength shift (BWS) at a 3 MGy dose is strongly reduced compared to responses of FBGs written with nonoptimized conditions. The BWS remains lower t…
Sentinel 2 and 3 for Temperature Monitoring Over the Amazon
2018
In this work we present results of an early assessment of the performance of the Land Surface Temperature (LST) product retrieved from the Sea and Land Surface Temperature Radiometer (SLSTR) on board the Sentinel-3 satellite (S3/SLSTR) over the Amazon basin. Results are validated from comparison of S3/SLSTR retrievals against in situ measurements of surface temperature collected over one instrumented site in the Peruvian Amazon. The validation exercise was performed on the standard S3/SLSTR Level-2 LST product as well as on a dedicated LST split-window algorithm with an explicit dependence on surface emissivity. Surface emissivity maps obtained from the high spatial resolution of S2/MSI are…
Numerical study of the accuracy of temperature measurement by thermocouples in small-scale reactors
2018
Proper temperature measurement is imperative in any laboratory study if reliable data are to be obtained, particularly in the field of chemical kinetics. In this paper we analyze in silico some typical thermowell configurations used in small-scale reactors by coupling computational fluid dynamics (CFD) with conjugated heat transfer phenomena. This allows us to identify deviations in measurements arising from thermal radiation and self-conductivity in mid and high temperature ranges, in addition to radial temperature gradients. A novel design is proposed and optimized by additional simulation, showing potential for faster and more accurate temperature measurements.
Correction for aerosol effects on satellite sea surface temperature measurements
1998
Estimation of Sea Surface Temperature (SST) from split- window algorithms for NOAA-AVHRR data can be determined with rms values of 0.7 K on a global basis. However, this figure is not compatible with the stringent accuracy of 0.3 K required by climate studies. Among the different sources of errors, the presence of tropospheric aerosols in the satellite field of view prevents the retrieval of accurate satellite SSTs. Still, the effect of aerosols on temperature measurements derived from remote sensing techniques has been traditionally overlooked. Very few studies have addressed the problem of giving split-window algorithms which incorporate aerosol correction, although retrieving algorithms …