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An all-fiber sensor scheme for simultaneous strain and temperature measurement is presented. The sensing head is formed by serially connecting a polarization maintaining photonic-crystal-fiber-based intermodal interferometer (IMI) with a fiber Bragg grating (FBG). The IMI, exhibiting an opposite strain response as compared to that of the FBG, is highly sensitive to strain, while it is insensitive to temperature. This has potential for improving the strain and temperature measurement resolutions. A sensor resolution of [+ or -] 8.3 [micro][epsilon] in strain and [+ or -] 2[degrees]C in temperature are experimentally achieved within a strain range of 0-957.6 [micro][epsilon] and a temperature range of 24[degrees]C-64[degrees]C, respectively. OCIS codes: 060.2310, 060.2370.

Two time-division-multiplexed (TDM) sources based on fiber Bragg gratings were applied to monitor gas temperature, [H.sub.2]O mole fraction, and C[H.sub.4] mole fraction using line-of-sight absorption spectroscopy in a practical high-pressure gas turbine combustor test article. Collectively, the two sources cycle through 14 wavelengths in the 1329-1667 nm range every 33 [micro]s. Although it is based on absorption spectroscopy, this sensing technology is fundamentally different from typical diode-laser-based absorption sensors and has many advantages. Specifically, the TDM lasers allow efficient, flexible acquisition of discrete-wavelength information over a wide spectral range at very high speeds (typically 30 kHz) and thereby provide a multiplicity of precise data at high speeds. For the present gas turbine application, the TDM source wavelengths were chosen using simulated temperature-difference spectra. This approach is used to select TDM wavelengths that are near the optimum values for precise temperature and species-concentration measurements. The application of TDM lasers for other measurements in high-pressure, turbulent reacting flows and for two-dimensional tomographic reconstruction of the temperature and species-concentration fields is also forecast. OCIS codes: 300.1030, 120.1740, 120.6780.

Accuracy, reliability, and long lifetimes are critical parameters for sensors measuring temperature in gas turbines of clean coal-fired power plants. Greener high efficiency next generation power plants need gas turbines operating at extremely high temperatures of 1500[degrees]C, where present thermocouple temperature probe technology fails to operate with reliable and accurate readings over long lifetimes. To solve this pressing problem, we have proposed the concept of a new hybrid class of all-silicon carbide (SiC) optical sensor; where a single crystal SiC optical chip is embedded in a sintered SiC tube assembly forming a coefficient of thermal expansion (CTE) matched all-SiC front-end probe. Because chip and host material are CTE matched, optimal handling of extreme thermal ramps and temperatures is possible. In this article, we demonstrate the first successful industrial combustor rig test of this hybrid all-SiC temperature sensor front-end probe indicating demonstrated probe structural robustness to 1600[degrees]C and rig test data to ~1200[degrees]C. The design of the rig test sensor system is presented and data are analyzed. [DOI: 10.1115/1.3204509] Keywords: temperature sensor, extreme environments, gas turbines, optical sensor

Estimation of evapotranspiration (ET) is important for monitoring crop water stress and for developing decision support systems for irrigation scheduling. Techniques to estimate ET have been available for many years, while more recently remote sensing data have extended ET into a spatially distributed context. However, remote sensing data cannot be easily used in decision systems if they are not available frequently. For many crops ET estimates are needed at intervals of a week or less, but unfortunately due to cost, weather, and sensor availability constraints, high resolution (< 100 m) remote sensing data are usually available no more frequently than 2 weeks. Since resolution of this problem is unlikely to occur soon, a modeling approach has been developed to extrapolate remotely sensed inputs needed to estimate ET. The approach accomplishes this by combining time-series observations from ground-based radiometers and meteorological instruments with episodic visible, near infrared, and thermal infrared remote sensing image data. The key components of the model are a vegetation density predictor and a diurnal land surface temperature disaggregator, both of which supply needed inputs to a surface energy balance model. To illustrate model implementation, remote sensing and ground-based experimental data were collected for cotton grown in 2003 at Maricopa, Ariz. Spatially distributed cotton canopy densities were forecasted for a 22-day interval using vegetation indices from remote sensing and fractional cover from ground-level photography. Spatially distributed canopy and soil surface temperatures were predicted at 15-min time steps for the same interval by scaling diurnal canopy temperatures according to time of day and vegetative cover. Considering that the predictions span a rapid growth phase of the cotton crop, comparison of spatially projected canopy cover with observed cover were reasonably good, with [R.sup.2]=0.65 and a root-mean-squared error (RMSE) of 0.13. Comparison of predicted temperatures also showed fair agreement with RMSE=2.1[degrees]C. These results show that combining episodic remotely sensed data with continuous ground-based radiometric data are a technically feasible way to forecast spatially distributed input data needed for ET modeling over crops. DOI: 10.1061/(ASCE)IR.1943-4774.0000169 CE Database subject headings: Evapotranspiration; Remote sensing; Temperature effects; Arizona. Author keywords: Evapotranspiration.

Width-increased dual-pump enhanced coherent anti-Stokes Raman spectroscopy (WIDECARS) is a technique that is capable of simultaneously measuring temperature and species mole fractions of [N.sub.2], [O.sub.2], [H.sub.2], [C.sub.2][H.sub.4], CO, and C[O.sub.2]. WIDECARS is designed for measurements of all the major species (except water) in supersonic combustion flows fueled with hydrogen and hydrogen/ethylene mixtures. The two lowest rotational energy levels of hydrogen detectable by WIDECARS are [H.sub.2] S(3) and [H.sub.2] S(4). The detection of these lines gives the system the capability to measure temperature and species concentrations in regions of flow containing pure hydrogen fuel at room temperature. OCIS codes: 120.1740, 300.6230.

Pyrometers are commonly used for high temperature measurement, but their accuracy is often limited by uncertainty in the surface emissivity. Radiation heating introduces additional errors due to the extra light reflected off the measured surface. While many types of specialized equipment have been developed for these measurements, this work presents a method for measuring high temperatures using single color pyrometers when the surface emissivity is unknown. It is particularly useful for correcting errors due to reflected light in solar heating applications. The method requires two pyrometers and is most helpful for improving measurement accuracy of low cost commercial instruments. The temperature measurements of two pyrometers operating at different wavelengths are analyzed across a range of sample temperatures to find the surface emissivity values at each wavelength that minimize the difference in temperature measurements between pyrometers. These are taken as the surface emissivity values, and the initial temperature measurements are corrected using the calculated emissivity values to obtain improved estimates of the surface temperature. When applied to temperature data from a solar furnace, the method significantly decreased the difference in the temperature measurements of two single color pyrometers. Simulated temperature data with both random noise and systematic errors are used to demonstrate that the method successfully converges to surface emissivity values and reduces temperature measurement errors even when subjected to significant errors in the model inputs. This method provides a potential low cost solution for pyrometric temperature measurement of solar-heated objects. It is also useful for temperature measurement of objects with unknown emissivity. [DOI: 10.1115/1.4000351] Keywords: pyrometer, solar heating, emissivity, temperature measurement, radiative heating

Temperature depression within the leading edge cavities on a space inducer is measured in Refrigerant 114 using miniature thermocouples mounted on the rotating blades. Time-averaged values of cavity temperature depression are determined all along the descent in cavitation number and correlated with the extent of cavities. In addition to mean values, temperature fluctuations are analyzed with respect to the onset of cavitation instabilities, namely, alternate blade cavitation and supersynchronous rotating cavitation. Temperature spectra relative to a rotating frame of reference are compared with pressure spectra obtained in a fixed frame of reference. Temperature oscillations issued from different blades are compared, and phase shifts between consecutive and opposite blades are evaluated in the case of the supersynchronous instability regime. [DOI: 10.1115/1.4001007]

In the present work, a picosecond lidar system aiming at single-ended combustion diagnostics in full-scale combustion devices with limited optical access, such as power plants, is described. The highest overall range resolution of the system was found to be OCIS codes: 120.1740, 280.3640, 280.1910, 280.6780.

We focus on the development of a remote temperature sensing technology, i.e., an optical laser-based sensor, using thermographic phosphors for medical applications, particularly within an electromagnetically hostile magnetic resonance imaging (MRI) environment. A MRI scanner uses a strong magnetic field and radio waves to generate images of the inside of the body. The quality of the image improves with increasing magnetic resonance; however, the drawback of applying a greater magnetic strength is the inducement of heat into the body tissue. Therefore, monitoring the patient's temperature inside MRI is vital, but until now, a practical solution for temperature measurement did not exist. We show europium doped lanthanum oxysulphide ([La.sub.2][O.sub.2]S:Eu) and terbium doped lanthanum oxysulphide ([La.sub.2][O.sub.2]S:Tb) are both temperature sensitive to a low temperature range of 10-50 [degrees]C when under ultraviolet (UV) excitation. The emission spectra and decay time characteristics of these phosphors were demonstrated. The results indicate that [La.sub.2][O.sub.2]S:Eu has a quenching rate of 13.7 m[degrees][C.sup.-1] and 4 m[degrees][C.sup.-1] at 512nm and 538nm, respectively. In addition, [La.sub.2][O.sub.2]S:Tb has a lower quenching rate of 4.19m[degrees][C.sup.-1] at 548nm due to its faster decay time. OCIS codes: 120.0120, 160.5690, 280.6780, 250.5230, 170.3650, 300.2530.

Fiber-optic single-point and quasi-distributed evanescent temperature sensors recoated with a blend of poly(methyl methacrylate) and poly(vinylidene fluoride) are proposed. Solid cladding enables the construction of small-size, low-cost, relatively wide-range and fast-response temperature sensors. The diameter of the sensor does not exceed the dimensions of the original optical fiber, while the response time of the sensor is 7.4 ms. Different mass ratios of polymers in the blend enable fine tuning of the applied cladding's refractive index. This allows the construction of sensors for different temperature ranges, while the application of all-silica graded-index multimode fibers enables the construction of quasi-distributed sensor systems with considerably reduced cross talk. OCIS codes: 060.2370, 120.6780, 120.7000, 160.5470, 280.6780.

Fiber-optic microsensors with a tip diameter of ~ 140 [micro]m have been developed that enable simultaneous measurement of dissolved oxygen (DO) and pH, and of DO and temperature (T), respectively. The tip of the optical fiber was covered with sensor compositions based on luminescent microbeads that respond to the respective parameters by a change in the decay time, intensity of their luminescence, or both. The use of microbeads enables the ratio of the signals to be easily varied, reduces the risk of fluorescence energy transfer between indicator dyes, and reduces the adverse effect of singlet oxygen that is produced in the oxygen-sensitive beads. The sensor chemistry for DO/pH was modified

A variational method to retrieve profiles of temperature, humidity, and cloud is described, which combines observations from a 12-channel microwave radiometer, an infrared radiometer, and surface sensors with background from short-range numerical weather prediction (NWP) forecasts in an optimal way, accounting for their error characteristics. An analysis is presented of the error budget of the background and observations, including radiometric, modeling, and representativeness errors. Observation errors of some moisture channels are found to be dominated by representativeness, due to their sensitivity to atmospheric variability on smaller scales than the NWP model grid, whereas channels providing information on temperature in the lowest 1 km are dominated by instrument noise. Profiles of temperature and a novel total water control variable are retrieved from synthetic data using Newtonian iteration. An error analysis shows that these are expected to improve mesoscale NWP, retrieving temperature and humidity profiles up to 4 km with uncertainties of < 1 K and < 40% and 2.8 and 1.8 degrees of freedom for signal, respectively, albeit with poor vertical resolution. A cloud classification scheme is introduced to address convergence problems and better constrain the retrievals. This Bayesian retrieval method can be extended to incorporate observations from other instruments to form a basis for future integrated profiling systems. Index Terms--Atmospheric measurements, microwave radiometry, remote sensing, variational methods.

Nowadays, thermal characterization of IC packages and packaging technologies is becoming a key task in thermal engineering. To support this by measurements, we developed a family of thermal test chips that allow a wide range of possible applications. Our chips are based on the same basic cell that is mainly covered by dissipating resistors and also contains a temperature sensor. These basic cells are organized into arrays of different size. The arrays are designed such that further 'super arrays' can also be built for tiling up larger package cavities. The first members of the family, TMC9 and TMC81, have been manufactured. Our measurements show that the goals aimed at the design have been achieved.

A primary thermometry system that can be used between 4.2 K and 0.65 K has been designed and constructed. It is made up of a thin-film resistive superconducting quantum interference device (SQUID) and DC-SQUID readout amplifier that are both fabricated on a single chip. A system bandwidth greater than 1 MHz with a white noise level less than 1 microphi(sub 0) per square root of hertz was attained when a DC-SQUID series array in direct readout flux-locked loop scheme was used.

The modeled performance of an Fe Boltzmann temperature lidar system is compared with existing Na narrow-band temperature techniques. The Fe Boltzmann technique employs mesospheric Fe as a fluorescence tracer and relies on the temperature dependence of the population difference of two closely spaced Fe transitions. The relative performance of the new technique is compared with an existing Na narrowband temperature technique, and a link analysis is performed with measured data for both Na and Fe. It is shown that for currently available laser technology the two systems yield similar performance but the Fe system allows for the use of more broadband lasers.

The need to develop interpolation-accurate temperature scales has resulted to the creation of the ITS-90, which is capable of determing the lower limit temperature of systems upto 0.65 Kelvin. Such a scale can be used to analyze liquid properties and other physical laws.

The use of a highly elliptical core two-mode fiber for simultaneous measurement of pressure (radial pressure or hydrostatic pressure) and temperature is presented. The sources of errors are discussed. Expressions are developed to calculate the cross sensitivities. From the numerical examples, some useful conclusions are given. Key words: Optical-fiber sensors, simultaneous measurement of pressure and temperature, cross sensitivity.

Assessment of the thermal environment at workplace and its effects on man require the measurement of mean radiant temperature, air temperature, humidity and air velocity. The use of an air temperature transducer with a precise platinum resistance temperature sensing element eliminates the effects of thermal radiation during air temperature measurements. Plane radiant temperature is measured using a transducer with two black-painted elements and two reflective gold-plated elements of the same size while a black globe thermometer helps measure mean radiant temperature. While air velocity is measured with sphere-shaped sensors, a dew- point transducer helps measure humidity.

The use of optical fiber in a temperature probe or sensor for optical pyrometry in the 100-1000 [degrees] C range is affected by the low thermal stability of classical fibers. We have studied the different sources of perturbations induced by exposure to high temperature. Two specific fibers especially suited for a high-temperature environment were tested and compared. Low (100 [degrees] C/min) and very fast (100 [degrees] C/s) fiber heating was performed to evaluate its influence on the guided flux and the induced error on temperature measurement. The metallic-coated fiber shows a reproducible temperature error that can be predicted. This important result permits the development of an uncooled fiber probe for temperature monitoring in high-temperature environments such as aerospace engines. Key words: Fiber-optic probe, bichromatic pyrometry, high temperature, thermal shocks, thermal emission.

Laser-induced fluorescence (LIF) observations of CH and C2 radicals in a dc-arcjet plasma are reported. A hydrogen and methane gas mixture flows through a dc-arc and expands through an orifice in the anode to form a luminous jet; diamond film grows under this jet on a water-cooled substrate. At the substrate position for best diamond growth, laser excitation spectra determine a rotational population distribution of CH(X) and C2(a), which yields Boltzmann gas temperatures of 2100 + or - 200 K. The C2 Swan-band emission from the same observation volume yields an excited C2(d) rotational and vibrational population distribution well described by a 5000 K temperature. The difference between the LIF and emission temperatures indicates that chemiluminescent reactions are the dominant excitation mechanism for the optical emission from the gas jet.

Energy storage measurements for capacitors and inductors are usually used to derive the quadratic relationships between stored energy and voltage or current. However, there are practical difficulties encountered in measuring very low temperature rises. A LM35 three-terminal integrated circuit temperature sensor was used to overcome these temperature measurement problems. The entire set-up is recommended for teaching capacitive and inductive energy storage in a first-year class.

A molecule that responds to heat and sends information about temperature in the form of a light signal is called a luminescent molecular thermometer (LMT) and it is able to function as a molecular-level thermometer. LMTs have a great advantage over other thermometers in measuring temperatures in a small space since the florescence detection is highly sensitive and enable one to observe even one molecule.

The telemetry system is used for remote temperature measurements, which includes a laser or a light emitting diode with a light guide. The experiment that demonstrates the telemetry of measurement data is described.

With data sets gained from Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) microwave channels, Geostationary Meteorological Satellite (GMS-5) infrared channels, and ship-measured data, the statistical algorithms to estimate sea surface temperature and near-sea surface air humidity around Taiwan and the South China Sea areas are developed. Then a new, improved method to estimate near-sea surface air temperature based on the algorithm proposed by Konda et al. [1] is established in this study. The results estimated with SSM/I data show that the root mean square error (RMSE) of SST, near-sea surface air humidity and air temperature over the oceans around Taiwan and the South China Sea are 1.2 K, 1.43 g/kg, and 1.6 K, respectively. The results with GMS data are 1.7 K, 1.71 g/kg and 1.7 K, respectively. The results also show that the improvements in the algorithm of Konda et al. [1] simplify the computation scheme, improve the accuracy, and match the regional ocean-atmosphere properties in retrieving near-sea surface air temperature. The estimate produced using SSM/I and GMS data also show good consistency between them, both in temporal and spatial variations. Basically, the accuracy of this result implies strong potential for application of satellite data to relative studies and operational work in the ocean-atmosphere interaction. Index Terms--Geostationary Meteorological Satellite (GMS), near-sea surface air humidity, near-sea surface air temperature, Special Sensor Microwave/Imager (SSM/I).

Magnetoelastic thick film sensors mechanically deform when subjected to a magnetic field impulse, launching elastic waves within the sensor the magnitude of which is greatest at the mechanical resonant frequency. As the sensors are magnetostrictive, the mechanical deformations launch magnetic flux that can be detected remotely. The characteristic resonant frequency of a magnetoelastic sensor, which is a function of the length, density, elasticity and Poisson's ratio of the sensor material, changes in response to temperature, pressure, ambient flow rate and, in combination with a mass changing, chemically responsive layer different analyte concentrations. By using an array of such sensors different environmental parameters can be simultaneously determined in a complex environment; we have designed and fabricated such an array for the simultaneous measurement of temperature and pressure. Index Terms--Magnetoelastic, remote query, sensor, wireless.

Radio-frequency (rf) beat frequencies between two longitudinal modes and two polarization modes of a birefringent dual-longitudinal-mode moire distributed-feedback fiber laser are employed to measure strain and temperature simultaneously. Operating entirely in the rf domain, this approach potentially allows one to employ low-cost and precise rf measuring techniques. A strain-temperature cross sensitivity of the strain- and the thermo-optic coefficients, which can be neglected in wavelength-based grating sensors, has been observed. The achieved sensor accuracy was [+ or -] 15 [micro][element of] and [+ or -] 0.2 [degrees] C. OCIS codes: 060.2370, 140.3490, 140.3510, 280.3420.

KatchAll Technology Group, Inc., a new, wholly owned subsidiary of KatchAll Industries International, is focusing on the development of high-tech software and hardware products for food service and other industries. [...]

The strain sensitivity of the fluorescence intensity ratio temperature-sensing technique has been measured to be (2 [+ or -] 3) x [10.sup.-4]%/[micro][Epsilon] in [Yb.sup.3+]-doped fiber, implying a temperature-to-strain cross sensitivity of (2 [+ or -] 3) x [10.sup.-4] [degrees] C/[micro][Epsilon]. The near-zero strain sensitivity means that this optical-fiber sensor technique is well suited for temperature measurement in strain-affected environments. [C] 2000 Optical Society of America OCIS codes: 060.2370, 120.6780, 160.5690, 300.2530.

Validation of thermocouple probes is vexatious at best, whereas calibration is just not done. Here is the problem: The thermocouple kit we use for hazard analysis critical control point (HACCP) [...]

The thermalization process of azulene was studied through a new molecular heater-thermometer system. The latter quickly generates thermal energy and detected with high temporal and spatial resolution. The thermalization can be described by the energy transfer from the solute to the solvent and the thermal diffusion among the outer solvents. Its rate was found to be faster than the vibration relaxation rate that was previously reported.