Remote Temperature Measurement Research Articles

Objective assessment of thermal effect of holmium laser (Hо:YAG) on biological tissue in an experiment

During the experiment the authors studied the specific features of Ho:YAG-laser effect on biotissues which made it possible to transfer the obtained data to applied medicine, specifically, to use holmium laser for ENT organs surgery, in particular, in case of tonsillectomy and adenotomy. The objective of our work was to study and reduce the thermal effect of holmium laser on biotissues. Biological objects (0.9% physiological saline solution and turkey meat) were subject to intratissual exposure of Ho:YAG-laser radiation for 5 seconds, after that remote temperature measurement of biological objects at the laser exposure area was made with thermal imager FLIR. Biological tissues are heated up to the temperature of 115±14°C, and the thermal damage area depends on laser exposure duration, power and laser radiation frequency, making from 1.5 to 5.0 mm. Under the conditions of cavitation and hydroshock (E = 0.6 J, R = 6 – 8 Hz, t = 5 sec) biotissue is heated by 12.1% of the initial ambient temperature and makes 21.1 °C, the heating area is restricted by the injected solution. The obtained data provide significant reduction of holmium laser thermal effect on biological objects, transfer of the obtained data to the applied medicine and active utilization of holmium laser in otorhinolaryngology, adapting it for surgical interferences on ENT organs, in particular, in case of tonsillectomy and adenotomy.

Temperature Sensor Using a Multiwavelength Erbium-Doped Fiber Ring Laser

A novel temperature sensor is presented based on a multiwavelength erbium-doped fiber ring laser. The laser is comprised of fiber Bragg grating reflectors as the oscillation wavelength selecting filters. The performance of the temperature sensor in terms of both wavelength and laser output power was investigated, as well as the application of this system for remote temperature measurements.

Quantifying Raman OH-band spectra for remote water temperature measurements.

Remote water temperature measurements by Raman scattering is a perspective tool for in situ and/or real-time studies for inaccessible areas such as the Arctic region. State-of-the-art laser remote temperature detection techniques are based on temperature-dependent transformation of the Raman OH stretching vibration band. This study compared different approaches quantifying Raman OH-band spectra transformation with temperature: the two-color technique, deconvolution procedure, Raman difference spectroscopy, and centroid technique. Distilled water was probed remotely by compact Raman LIDAR, and the results demonstrated that the Raman OH-band centroid technique achieved the best temperature measurement accuracy (±0.15°C).

Remote-sensing gas measurements with coherent Rayleigh-Brillouin scattering

We measure the coherent Rayleigh-Brillouin scattering (CRBS) signal integral as a function of the recorded gas pressure in He, Co2, SF6, and air, and we confirm the already established quadratic dependence of the signal on the gas density. We propose the use of CRBS as an effective diagnostic for the remote measurement of gas' density (pressure) and temperature, as well as polarizability, for gases of known composition.

Quality Engineering Tools Focused on Designing Remote Temperature Measurements for Inaccessible Locations by Using Light Components Parameterization of the Heated Materials

This paper is focused on research dedicated to measure the bucket wheel bearing temperature of the bucket wheel excavator (BWE). It proposes a measurement method for heating friction materials because is difficult to detect the temperature variation in the bearing. The major issue is to detect the generated infrared light according to the material detection. The temperature is considered the major signal of the wheel reliability and a remotely temperature detection method is proposed and because the sleeve bearing is a crucial part of the excavator a predictive measurements system for buckled wheel axis system was designed.

A broadening temperature sensitivity range with a core-shell YbEr@YbNd double ratiometric optical nanothermometer.

The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ∼980 to the more relevant ∼808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd → Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle based optical nano-thermometer under single ∼808 nm wavelength photo-excitation from around ΔT = 150 K to over ΔT = 300 K (150-450 K). Such engineered nanocrystals are suitable for remote optical temperature measurements in technology and biotechnology at the sub-micron scale.

INVITED] Multiwavelength operation of erbium-doped fiber-ring laser for temperature measurements

In this work, simultaneous lasing at up to eight wavelengths is demonstrated in a multi-wavelength erbium-doped fiber ring laser previously reported. This is achieved by introducing a feedback fiber loop in a fiber ring cavity. Eight-wavelength laser emission lines were obtained simultaneously in single-longitudinal mode operation showing a power instability lower than 0.8dB, and an optical signal-to-noise ratio higher than 42dB for all the emitted wavelengths. The fiber Bragg gratings give this source the possibility to be also used as sensor-network multiplexing scheme. The application of this system for remote temperature measurements has been demonstrated obtaining good time stability results.

Spatially resolved remote measurement of temperature by neutron resonance absorption

Deep penetration of neutrons into most engineering materials enables non-destructive studies of their bulk properties. The existence of sharp resonances in neutron absorption spectra enables isotopically-resolved imaging of elements present in a sample, as demonstrated by previous studies. At the same time the Doppler broadening of resonance peaks provides a method of remote measurement of temperature distributions within the same sample. This technique can be implemented at a pulsed neutron source with a short initial pulse allowing for the measurement of the energy of each registered neutron by the time of flight technique. A neutron counting detector with relatively high timing and spatial resolution is used to demonstrate the possibility to obtain temperature distributions across a 100µm Ta foil with ~millimeter spatial resolution. Moreover, a neutron transmission measurement over a wide energy range can provide spatially resolved sample information such as temperature, elemental composition and microstructure properties simultaneously.

Oxygen rotational temperature determination using empirical analyses of C(3)Π(v' = 2) ← X(3)Σ(v'' = 0) transitions.

The spectra of molecular oxygen through C(3)Π(v' = 2) ← X(3)Σ(v'' = 0) transitions have been obtained by coherent microwave Rayleigh scattering (radar) from resonance-enhanced multiphoton ionization (REMPI). Measurements of rotational temperatures of molecular oxygen have been demonstrated based on the empirical analyses of the O2 spectra without the requirement of highly resolved rotational features. Three methods, including (1) linewidth fitting, (2) linear fitting, and (3) area fitting have been investigated for temperature measurements within pure oxygen, ambient air, and H2-air and CH4-air flame environments. The first two methods were applied in a moderately low temperature environment with measurement uncertainties less than 11% and 26%, respectively. The area fitting method covered a wider temperature range, from room temperature (~300 K) to flame temperature (~1700 K), with minimal dependence on the fine structures of the O2 spectra. Less elaborate than Boltzmann plot analyses of ultrafine rotational lines from congested upper rotational energy levels in O2(C(3)Π(v' = 2)), these empirical analyses are predictably sensitive to the thermal distribution of molecular oxygen and have been successfully demonstrated as simple and quick methods for remote gas-phase temperature measurement.

Influence of cutting parameters on the chip-tool interface temperature during the turning of Waspaloy

Abstract Waspaloy, as a nickel superalloy, is a difficult-to-machine material used for gas turbine engine components that require considerable strength and corrosion resistance at high operating temperatures. The machining of nickel-based alloys generates high temperatures at the cutting tool edge. This research investigated the relationship between cutting parameters and cutting temperature, using a remote temperature measurement method employing an infrared thermometer. In addition, the effects of cutting parameters on surface roughness were examined. Experiments were conducted on Waspaloy AMS5708 superalloy samples and a PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. It was observed that the highest cutting speed and highest feed rate generated higher temperatures and higher surface roughness. Better surface roughness was obtained with the lowest feed rate, the highest cutting speed and the higher cutting depth. No cutting fluid was used in the experiments.

Measuring subcutaneous temperature and differential rates of rewarming from hibernation and daily torpor in two species of bats

Prolonged and remote measurement of body temperature (Tb) in undisturbed small hibernators was not possible in the past because of technological limitations. Although passive integrated transponders (PITs) have been used previously to measure subcutaneous temperature (Tsub) during daily torpor in a small marsupial, no study has attempted to use these devices at Tbs below 10°C. Therefore, we investigated whether subcutaneous interscapular PITs can be used as a viable tool for measuring Tb in a small hibernating bat (Nyctophilus gouldi; Ng) and compared it with measurements of Tb during daily torpor in a heterothermic bat (Syconycteris australis; Sa). The precision of transponders was investigated as a function of ambient temperature (Ta) and remote Tsub readings enabled us to quantify Tsub–Tb differentials during steady-state torpor and arousal. Transponders functioned well outside the manufacturer's recommended range, down to ~5°C. At rest, Tsub and rectal Tb (Trec) were strongly correlated for both bat species (Ng r2=0.88; Sa r2=0.95) and this was also true for N. gouldi in steady-state torpor (r2=0.93). During induced rewarming Tsub increased faster than Trec in both species. Our results demonstrate that transponders can be used to provide accurate remote measurement of Tb in two species of bats during different physiological states, both during steady-state conditions and throughout dynamic phases such as rewarming from torpor. We show that, at least during rewarming, regional heterothermy common to larger hibernators and other hibernating bats is also present in bats capable of daily torpor.

Development of a fiber-optic temperature sensor for remote measurement of the water temperature in a spent nuclear fuel pool

A fiber-optic temperature sensor (FOTS) using an infrared optical fiber was developed and applied to remote and real-time measurements of the temperature of the water in a spent nuclear fuel pool (SNFP) at a nuclear power plant (NPP). In this study, metal caps were employed as the sensing probe of the FOTS owing to their high thermal conductivity. An infrared optical fiber, PIR AgCl:AgBr polycrystalline fiber, was used to transmit the infrared light emitted from the water at a certain temperature. The FOTS was used to measure the temperature of the water in oil bath by changing the temperature in 5 °C increments over the range from 30 to 70 °C. The temperatures measured by using the FOTS with a metal cap varied almost linearly over that range, which means that the FOTS with a metal cap can be used as an auxiliary monitoring system for measuring the temperature of the water in a SNFP water temperature.

Field Test of Detection and Characterisation of Subsurface Ice using Broadband Spectral-Induced Polarisation

Low-frequency (LF, <<1 kHz) electrical resistivity is useful in discriminating frozen from unfrozen ground in periglacial environments, but it cannot distinguish whether frozen materials are dry or ice-rich, nor can it provide reliable estimates of ice content. However, polarisabilities due to unfrozen, interfacial water and protonic defects in ice both have strong dielectric relaxations (frequency dependence), resulting in a large decrease in resistivity at high frequencies (HF, > > 1 kHz). From laboratory measurements of samples collected at the US Army Permafrost Tunnel (Fox, Alaska), we find temperature-dependent relationships between ice volume fraction and the resistivity frequency effect (RFE, defined as the LF-normalised difference in LF and HF resistivities). We report the first field detection of H2O polarisability in permafrost, using a broadband spectral-induced polarisation system at the permafrost tunnel. By comparing laboratory and field spectra, we found a best-fitting ice temperature of -3 ± 0.5 °C. Laboratory RFE at the selected temperature was then used to map the RFE in the tunnel wall to 45 − 95 per cent ice by volume. Both of these results agreed quantitatively with the bulk properties of the tunnel, and the ice content image correlated qualitatively with major permafrost features. The RFE approach may be expedient using simpler instrumentation, but the close agreement of laboratory and field spectra indicates that the ice and interfacial water signatures can be individually quantified by broadband fitting of both amplitude and phase. This will provide more accurate constitutive relations, but more importantly will yield better remote temperature measurement of the subsurface using known dependencies of the dielectric relaxation frequencies. Copyright © 2015 John Wiley & Sons, Ltd.

Stable Multiwavelength Erbium Fiber Ring Laser With Optical Feedback for Remote Sensing

In this paper, we demonstrate a stable fiber sensing system for remote temperature measurements, where the sensing element is an array of four fiber Bragg gratings and sensor interrogation is achieved with a multiwavelength erbium fiber ring laser. By introducing a feedback fiber loop in a fiber ring cavity, four laser emission lines were obtained simultaneously in single-longitudinal mode operation (SLM). The power instability obtained was lower than 0.5 dB with an optical signal-to-noise ratio higher than 50 dB for all the emitted wavelengths. The application of this system for remote temperature measurements has been demonstrated even though the SLM regime cannot be preserved.

Telemetry with an Optical Fiber Revisited: An Alternative Strategy

With a new data-acquisition system developed by PASCO scientific, an experiment on telemetry with an optical fiber1,2 can be made easier and more accurate. For this aim, an alternative strategy of the remote temperature measurements is proposed: the frequency of light pulses transmitted via the light guide numerically equals the temperature using known manufacturer's data or an initial calibration step. The additional equipment for the experiment is reduced to a minimum.

Investigations Regarding the Influence of Surface Topography on Emissive Properties of Material

In the paper analysis of surface topography influence on emissivity of metals was shown. This was performed for infrared band comprising wavelength region of 7.5 13 micrometers. Appropriate characterization and description of object emissivity has a crucial influence on accuracy of IR system for remote temperature measurement, e.g. IR thermography or pyrometry. These properties depend on many factors, including surface topography of material, where especially cavities play a very important role. In references so far emissivity are discussed mainly as influence of type of material (metal, dielectric), its temperature, wavelength or direction of emission. In the paper characterizing emissivity of construction materials in connection with 3D surface topography.

Optical temperature sensor using speckle field

This paper presents a newly developed, laserbased, noncontact and remote temperature sensor suitable for high as well as low temperature measurements, which can be adapted to a commercial tensile testing machine equipped with an electrical furnace to monitor temperature. It can also be a miniaturized sensor for remote measurement of body temperature for biomedical diagnostics (e.g. as a sensor integrated into an endoscope to measure internal temperature during surgical procedure). The basic principle of the sensor is based on determining the changes occurring to a secondary speckle pattern generated by the scattered laser beam from a rough surface. In the present case a rough metal surface is used. As the surface of the metal plate changes due to cantilever action when exposed to heat, the resulting speckle pattern also changes. This change in the speckle pattern is computed by comparing it to a reference speckle pattern recorded at known temperature and can so be related to the temperature change. From the value of correlation coefficient we were able to measure the temperature. Furthermore, the paper presents the description of the signal processing algorithm and the optical arrangement. Based on the experimental data, it can be shown that this sensor can be successfully used for the remote extraction of temperature.

Communication techniques and challenges for wireless food quality monitoring.

Remote measurement of product core temperature is an important prerequisite to improve the cool chain of food products and reduce losses. This paper examines and shows possible solutions to technical challenges that still hinder practical applications of wireless sensor networks in the field of food transport supervision. The high signal attenuation by water-containing products limits the communication range to less than 0.5 m for the commonly used 2.4 GHz radio chips. By theoretical analysis of the dependency of signal attenuation on the operating frequency, we show that the signal attenuation can be largely reduced by the use of 433 MHz or 866 MHz devices, but forwarding of messages over multiple hops inside a sensor network is mostly unavoidable to guarantee full coverage of a packed container. Communication protocols have to provide compatibility with widely accepted standards for integration into the global Internet, which has been achieved by programming an implementation of the constrained application protocol for wireless sensor nodes and integrating into IPv6-based networks. The sensor's battery lifetime can be extended by optimizing communication protocols and by in-network pre-processing of the sensor data. The feasibility of remote freight supervision was demonstrated by our full-scale 'Intelligent Container' prototype.

Comparison of Satellite-Derived Land Surface Temperature and Air Temperature from Meteorological Stations on the Pan-Arctic Scale

Satellite-based temperature measurements are an important indicator for global climate change studies over large areas. Records from Moderate Resolution Imaging Spectroradiometer (MODIS), Advanced Very High Resolution Radiometer (AVHRR) and (Advanced) Along Track Scanning Radiometer ((A)ATSR) are providing long-term time series information. Assessing the quality of remote sensing-based temperature measurements provides feedback to the climate modeling community and other users by identifying agreements and discrepancies when compared to temperature records from meteorological stations. This paper presents a comparison of state-of-the-art remote sensing-based land surface temperature data with air temperature measurements from meteorological stations on a pan-arctic scale (north of 60° latitude). Within this study, we compared land surface temperature products from (A)ATSR, MODIS and AVHRR with an in situ air temperature (Tair) database provided by the National Climate Data Center (NCDC). Despite analyzing the whole acquisition time period of each land surface temperature product, we focused on the inter-annual variability comparing land surface temperature (LST) and air temperature for the overlapping time period of the remote sensing data (2000–2005). In addition, land cover information was included in the evaluation approach by using GLC2000. MODIS has been identified as having the highest agreement in comparison to air temperature records. The time series of (A)ATSR is highly variable, whereas inconsistencies in land surface temperature data from AVHRR have been found.

Inverse Determination of Interfacial Wear Temperatures with a Receding Boundary and the Implications for Tribotesting

Frictionally generated interfacial temperatures are of great interest during tribotesting and candidate materials evaluations, as well as from actual components in service. Unfortunately, it is very difficult, if not impossible, to directly interrogate the interacting surfaces for these temperatures, especially when the wear surface is receding. Though remote measurements of temperature or strain are usually obtainable, they can only hint at the frictional temperatures unless they are just below the surface and, thus, quickly vulnerable to wear damage. In order to overcome these inherent difficulties, a least-squares enforcement of remote temperature data was used with a direct analytical solution for a cylindrical specimen with a receding surface to determine the interfacial temperatures as a function of time. Comparisons between the direct and inverse analytical solutions, as well as resulting interfacial predictions, based on existing data showed excellent agreement and verified the ability of the method to determine temperatures based on remote data. As expected, stray transfer from the lateral surface of the pin, specimen dimensions, as well as the recession velocity of the surface clearly influenced the interfacial temperature history and will therefore have important ramifications for tribotesting and the evaluation of the results.