Abstract: A photonic quantum dew point sensor determines a dew point of an analyte and includes a common substrate; a photonic dew sensor on the common substrate and exposed for direct contact with the analyte; a photonic temperature sensor on the common substrate; an optomechanical temperature sensor on the common substrate; a dew sensor substrate interposed between the photonic dew sensor and the common substrate; a heater on the dew sensor substrate proximate to the photonic dew sensor; a temperature sensor substrate interposed between the common substrate and each of the photonic temperature sensor and the optomechanical temperature sensor; and a sensor cover on the photonic temperature sensor, the optomechanical temperature sensor, and the temperature sensor substrate to cover the photonic temperature sensor and the optomechanical temperature sensor to prevent direct contact between the analyte and each of the photonic temperature sensor and the optomechanical temperature sensor.

Abstract: A vapor-condensation-assisted optical microscopy system comprises a vapor-condensation-assisted device and an optical microscope. The vapor-condensation-assisted device comprises air blowing device, a vapor producing device and a guide pipe. The vapor producing device connects the air blowing device with the guide pipe. The optical microscope comprises an observing device, an image processing device, a support frame and a stage. The stage, the guide pipe of the vapor-condensation-assisted device, the observing device, and the image processing device are fixed on the support frame. The vapor-condensation-assisted device is configured to provide a vapor to sample on the stage in application.

Abstract: A therapeutic laser with a source of pulsed electromagnetic radiation, a control device for controlling the intensity and/or the duration of the therapeutic laser applied to the tissue, and a detection device for detecting optoacoustic signals triggered by irradiating the living tissue with the pulsed electromagnetic radiation. The therapeutic laser is characterized by an evaluation device that acts on the control device and is used for calculating a degree of quality B(t) from the optoacoustic signals detected by the detection device for individual laser pulses applied to a predetermined laser spot and determining a fit function f(t) at a predetermined point in time ?t1, the fit function f(t) approximating the mean curve of B(t) for 0?t??t1. The intensity and/or the irradiation time of the therapeutic laser is defined by the parameters for the predetermined laser spot, the parameters being determined for the fit function f(t).

Abstract: A system includes a sensing cell having a walled structure configured to receive a fuel sample within an interior space of the walled structure. The sensing cell also has at least one cooling surface located on at least a portion of the walled structure and configured to cool the fuel sample. The sensing cell further has an optical port configured to couple to one or more optical fibers and to provide first radiation to the fuel sample. In addition, the sensing cell has a mirror configured to reflect the first radiation in order to provide second radiation to the optical port. The optical port defines a collinear optical geometry for providing the first radiation to the fuel sample and receiving the second radiation through the fuel sample. The system also includes at least one cooler configured to cool the fuel sample in the sensing cell by cooling the at least one cooling surface.

Abstract: In one embodiment, a system includes a first cold noise source, a first radiometer receiver, and a first detector. The first cold noise source generates a first thermal radiation signal having a first carrier frequency band. The first thermal radiation signal carries a first information signal. The first cold noise source also transmits the first thermal radiation signal through a first antenna. The first radiometer receiver receives the first thermal radiation signal through a second antenna, and the first detector extracts the first information signal from the first thermal radiation signal.

Abstract: The invention relates to a method and a sensor for determining the hydrocarbon dew point in a gas, in particular in a gaseous fuel. According to the invention a roughened condensation surface is provided on a planar measurement surface of a transparent body. Light is shone onto the roughened condensation surface through the transparent body and the intensity of the light reflected back into the transparent body is measured. The hydrocarbon dew point temperature can be inferred from changes in the intensity of the light which is reflected back when heating or cooling the condensation surface.

Abstract: A new method and apparatus is described for measurement of the dew point, and thus the vapor pressure of various gases and gas mixtures. In this method an optical element which is exposed to a gas atmosphere is cooled while its temperature is being monitored. At the same time an optical signal is sent through the back of the optical element. The optical signal goes through internal reflections. As soon as dew forms on the surface of the element, the optical signal will exhibit selective absorption due to the interaction of the evanescent tail of the optical signal and based on the chemical nature of the condensate. This invention can also be used to characterize condensable content of gas mixtures. The method allows for the spectral characterization and determination of the condensed vapor. It offers several advantages over existing methods.

Abstract: The long-side surface of a triangular prism is a detection surface. The distal end portions of coaxial light-emitting/light-receiving optical fiber cables are joined to one short-side surface of the prism. A thermoelectric cooling element is mounted on the other short-side surface of the prism. A mirror is provided between the cooling surface of the thermoelectric cooling element and the short-side surface. When dew condensation occurs on the detection surface, part of light applied from an optical fiber on the light-emitting side onto the lower surface of the detection surface exits from the prism through the condensed dew. The specular reflection returns to the lower detection surface by a mirror surface and is specularly reflected again. The specular reflection then enters an optical fiber on the light-emitting side. Dew condensation on the detection surface is detected by a change in the intensity of light received through the optical fiber.

Abstract: The present invention provides an intensity modulated optical fiber temperature switching immersion probe for remote temperature monitoring and switching of an industrial process. The present invention also provides a method for remote sensing of temperature.

Abstract: The apparatus for determining the dew-point and/or the content of vapor in the air, particularly for the use in radio sondes, comprises a dew-point mirror assembly, including a source of light, a reflector, a cooling element thermally coupled to the reflector, a temperature sensor for measuring the temperature of the reflector, and a detecting sensor for receiving the light emitted by the light source and reflected by the reflector. The detecting sensor is located in a temperature stabilized region of the apparatus and optically coupled to the reflector by means of a light wave conductor. The light source is an incandescent lamp. A sensor head is provided that receives the reflector, the cooling element, the light source, and the input end of the light wave conductor. The sensor head is heated by means of an active heating element.

Abstract: A fiber optic hygrometer apparatus and method for sensing and measuring the dew point of an atmosphere is disclosed that includes a controller for controlling the operation of the apparatus and a first optical fiber for transmitting light energy from a source of light energy to an optical core extending into the atmosphere being monitored. The optical core includes an end that is prepared as a reflecting surface, allowing the light energy reaching the optical core to be internally reflected back toward the source. A second optical fiber captures the light energy internally reflected from the optical core and conveys the captured light energy to a light energy detector. The light energy detector is arranged to output signals to the controller representing the magnitude of the light energy captured. A cooling device and a temperature-sensing device operationally connected to the controller are attached to the optical core.

Abstract: A novel method for measuring a deposit point is provided, which makes it possible to quickly and accurately measure a cloud point. A test sample is irradiated at an angle of incidence .theta. with an incoming light beam which satisfies an expression .theta.<.theta..sub.2 while gradually cooling the test sample such as gas oil, and a totally reflected light beam from the test sample is detected for every temperature, provided that .theta..sub.2 represents a critical angle of total reflection of a deposit such as a paraffin component deposited when the test sample is cooled. The deposit point of the test sample is determined from a change in intensity of the totally reflected light beam with respect to the change in temperature. The light intensity distributions, detected by a sensor array at respective temperatures, are statistically processed to more accurately determine the deposit point.

Abstract: A cycling chilled mirror hygrometer is described wherein the mirror employed comprises a sapphire substrate having deposited thereon alternating layers of titanium dioxide and silicon dioxide. The surfaces resulting from the described technology yield a ten fold enhancement over the "theoretically pure" optical surface characteristics achieved with the prior art gold mirrors. Additionally, these devices have provided ideal surface characteristics for 350 degree optical triangulation, thereby permitting greater primary sensor sensitivity at low humidity levels (below -40 Cdp) and the elimination of long term "optical reflective gain" variations due to aging characteristics as compared with the conventional gold mirrors having impurities.

Abstract: A dew or frost point temperature hygrometer wherein a reflective surface, which is cooled by a cryogenic source and held at the dew or frost point temperature by a servo control, reflects light from a light source to a light detector. Very low concentrations of moisture or frost which condense on the reflective surface are measured very rapidly as a change in light reflected from that surface. No re-calibration is needed throughout its exceedingly wide moisture measurement range of from less than 1 part per billion to about 30 parts per thousand within a range of temperature from about -110.degree. C. to about 30.degree. C.

Abstract: A dew or frost point hygrometer wherein a reflective surface, which is cooled by a cryogenic source and held at the dew or frost point-temperature by a servo control, reflects light from a light source to a light detector. Very low concentrations of moisture or frost which condense on the reflective surface are measured very rapidly as a change in light reflected from that surface. No re-calibration is needed throughout its exceedingly wide moisture measurement range of from about 1 ppb to about 30 ppm within a temperature range of from about -110.degree. C. to about 30.degree. C.

Abstract: An elongated mirrored surface has a temperature gradient established thereacross. Condensation forms along the mirrored surface and the edge of the condensation next to the portion of the mirrored without condensation is where the dew point temperature exists. A scanning means is provided for locating this edge of the condensation. Temperature sensing means, located at the edge, measures the dew point temperature.

Abstract: The invention is directed to chemical compositions suitable for use in salt-solution transition temperature or hot mirror devices. It also provides methods of using these sensors (for the measurement of the humidity of gases) as well as the apparatus. The chemical composition which of itself senses the changes of water vapor pressure is birefringent at a first water vapor pressure and temperature, but non-birefringent at a second vapor pressure and temperature. The optical changes which accompany these phase changes may be amplified with polarizers. The means for heating the chemical composition can vary widely. Various thermometric devices can be used for temperature sensing. The accuracy required of the particular instrument model, the device's configuration, and the other components, selected for the particular system all affect the choice of thermometric device selected.

Abstract: The dew points of condensible hydrocarbon and water in a gas stream are determined independently in a single run by observing changes in intensity of light scattered from a mirror surface which is cooled to below both of the dew points. A decrease in intensity denotes the hydrocarbon dew point while an increase in intensity denotes the water dew point. The apparatus is simple and operates automatically. The mirror surface has a first polished and highly reflective portion and a second, roughened, less reflective portion. The intensity of scattered light is preferably monitored separately for each mirror portion.

Abstract: An apparatus for measuring dew-point of a gas stream includes a sensor cell having a probe, means for cooling the probe, means for transmitting light to the probe surface in a pressurized chamber, means for receiving returned light scattered from the cooled probe surface, and means for determining dew-point from a reduction in scattered light intensity. The probe surface is provided in its center with a depression of low angle.