Abstract: A compound sensor which can improve the space for installing sensors and an operation for installing sensors by organizing various types of sensors, are provided. A compound sensor according to the present invention includes a light-shielding plate (3A) having one face onto which sunlight is irradiated and the other face located on a side opposite to the one face, which shields the sunlight from the one face side toward the other face side, a solar sensor (8A-8C) provided in the one face of the light-shielding plate (3A), and a temperature sensor provided in the other face side of the light-shielding plate (3A).

Abstract: An exhaust emission analysis system is provided that includes an exhaust and dilution gas source respectively providing exhaust and dilution gases. A dilution unit includes exhaust and dilution gas mass flow controllers, fluidly connected to the exhaust and dilution gas sources. The mass flow controllers define a gas flow rate of gas from their respective gas source. A connection mixes the gases to provide a diluted exhaust gas having an incorrect dilution ratio. A water measurement device measures the water content of the exhaust gas. A water content dilution signal is sent from the water measurement device to a control device. An adjustment factor is calculated by the controller and a flow rate command signal is sent from the controller, to the exhaust gas mass flow controller to adjust the gas flow rate of the exhaust gas and provide a corrected dilution ratio at the connection.

Abstract: The application relates to a chemical sensor device comprising a substrate (1), a sensor medium (3) formed on the substrate, the sensor medium comprising one-dimensional nanoparticles, wherein the one-dimensional nanoparticles essentially consist of a semiconducting AxBy compound, e.g. V2O5 and detection means (2) for detecting a change of a physical property of the sensor medium e.g. conductivity. The porosity of the sensor medium supports a fast access of the analyte to the sensing material and therefore a fast response of the sensor. The selectivity and sensitivity of the sensor can be tailored by doping the one-dimensional nanoscale material with different dopants or by varying the dopant concentration. Sensitivity of the sensor device to an analyte, preferably an amine, can be increased by increasing relative humidity of the sample to at least 5%.

Abstract: A hydrocarbon liquid-seal device is provided. The device includes first and second conduits in fluid communication with each other such that the first and second conduits define a flow path therethrough configured to pass a hydrocarbon vapor. The first and second conduits are in a spaced relationship and are not rigidly coupled to one another for isolating a vibration or movement respectively therein. The device further includes a liquid disposed within a space between first and second end portions of the first and second conduits, respectively, such that the liquid blocks the space between the first and second end portions and seals the hydrocarbon vapor in the flow path.

Abstract: A humidity sensing structure having a cantilever resistor and a method for fabricating the same are disclosed. The method includes providing a substrate having a first surface and a second surface; performing an oxidation process on the first surface and the second surface to form a first oxide layer and a second oxide layer respectively; forming a resistance sensing layer on the first oxide layer; forming a humidity sensing layer on the resistance sensing layer; forming in the substrate a through-hole penetrating the first oxide layer and the second oxide layer; and forming a cantilever in the through-hole such that both the humidity sensing layer and the resistance sensing layer are secured in position on the cantilever. In response to humidity changes, the humidity sensing layer varies in volume and in consequence the resistance sensing layer varies in length, allowing ambient humidity to be measured.

Abstract: A device for taking ultra-high frequency hydrometric measurements by generating sine wave trains of incident wave(s) at frequencies assuming several values in arithmetic progression between a few MHz and a few GHz, and has at least one ultra-high frequency cable. The cable includes at least two measuring stations (4) spaced along the cable a predetermined distance apart, each measuring station (4) having a measuring cell (14) and a separator device capable of only sampling a portion of the incident wave(s) with sufficient energy for each measuring cell to send back an echo measurable by electronic read-out device so that the sampling of the incident wave(s) by each measuring station occurs essentially simultaneously. Each measuring cell (14) consists of an ultra-high frequency line portion with its distal end terminated by a short circuit and with the line portion having a circumferential external wall which is either porous or provided with ports.

Abstract: A method for correcting humidity measurement results of a radiosonde, especially for errors resulting from radiative heat exchange. Environmental humidity Um is measured with a humidity sensor in the radiosonde, a current value of at least one environmental condition parameter is determined, and error-corrected humidity U is calculated directly or indirectly utilizing the measured environmental humidity Um and a correction value corresponding to the at least one current environmental condition parameter value.

Abstract: A kit includes at least one of: a substance for one of ingestion by a human body and application to one of the skin, the mucous membranes, hair, and the nails; a cosmetic applicator; and a makeup accessory. The kit also includes at least one of: an indicator of ambient humidity; and a sensor of ambient humidity.

Abstract: A duct mounted environmental sensing unit includes a plurality of sensors for detecting respective parameters of a fluid in a duct. The sensing unit enables at least three sensors to make contact with the fluid through a single insertion point in the duct.

Abstract: A system and method for identifying molecules. Molecules are identified from a gaseous matter having the molecules and flowing at two different flow rates. A system and method for identifying a substance. A particle which is indicative of a substance is identified from matter having the particle and flowing at two different flow rates. After the particle is identified, the substance is identified.

Abstract: Systems and methods include a test media, a reservoir containing fluid, and a sensor compared to measure a parameter that is related to an amount of fluid in the test media. Systems and methods may include a comparator to compare the parameter measurement to a parameter set point. Systems and methods may include a control system to control the addition of the fluid to the test media so that the parameter is maintained at a steady state value.

Abstract: An energy-autonomous sensor for detection of physical environmental parameters, having at least one sensor element, one storage element and one control circuit, with a timer circuit which is activated on reaching a predetermined electrical voltage on the storage element, activates the sensor and the control circuit at predetermined time intervals, and deactivates them after a predetermined operating time, such that this results in a time duration of sensor operation and a sensor operation pause.

Abstract: A nano-particle containing apparatus, a nano-particle detection system and a method are disclosed. The nano-particle containing apparatus includes a casing, an air extracting device, a pressure device and a measuring instrument. The casing has a containing space for disposing a plurality of nano-particles. An internal wall surface of the casing has active self-cleaning function. The pressure control device controls the pressure status of the containing space. The active self-clean function is that nano-particles adhered to the internal surface wall are removed into the containing space. The nano-particles then are pumped by the air extracting device from the containing space. The measuring instrument then detects the status of an object affected by the nano-particles after the object is delivered into the containing space.

Abstract: A measuring device for detecting a humidity and temperature of a window surface including at least one moisture sensor and at least one temperature sensor placed on the window surface, an evaluation unit connected downstream from the moisture and temperature sensors, and a signal converting and linking unit placed between the moisture and temperature sensors and the evaluation unit. Further, when the temperature sensor detects a change in a temperature of the window surface or the moisture sensor detects a change in a moisture of the window surface, a frequency of an oscillator included in the signal and converting unit is changed.

Abstract: Methods and systems for measuring atmospheric water content, are provided. The method includes measuring a first air temperature and a first air pressure at a first location in a compressor, measuring a second air temperature and a second air pressure at a second location in the compressor, computing a ratio of specific heats from the first and second air temperatures and the first and second air pressures, and determining an atmospheric water content from the ratio of specific heats.

Abstract: The invention provides a humidity-sensitive element using, as a humidity-sensitive film, a polyimide having a molecular structure capable of forming a network structure at a high density, exhibiting less drift after being left standing at a high temperature and a high humidity and having excellent characteristics. A humidity-sensitive element according to the invention uses the polyimide obtained by dehydrating and ring closing a polyamide acid forming a network structure in which terminals of basic molecular chains are interconnected with one another, as a humidity-sensitive film. The humidity-sensitive element of the invention suitably uses a polyimide, in which terminals of basic molecular chains are interconnected with one another by use of triamine or a tricarboxylic acid, as a humidity sensitive film.

Abstract: A sensor arrangement for detecting fogging on a glass pane, the arrangement including a support plate, a sensor element in thermal communication with the glass pane, wherein the sensor element is arranged on the support plate and is sensitive to moisture and a contact element that thermally couples the sensor element with the glass pane. The contact element is fastened on the support plate so as to enclose the support plate to a large extent in a contact area where the contact element contacts the glass pane.

Abstract: Very small projections (10-2) are arranged on a mirror surface (10-1) of a mirror (10). The shape of a projection (10-2) is not limited to a circular cone, but it can be a hollow-cylindrical shape, semispherical shape, or square prism shape, and also, it can be a polyhedron with many faces. With a reduction in temperature of the mirror (10), water vapor contained in a gas to be measured condenses on the mirror surface (10-1) of the mirror (10). In this case, because of the very small projections (10-2) on the mirror surface (10-1), the condensation is promoted by the projections (10-2) serving as the cores. This facilitates condensation even at low dew points and improves response. Further, the size of condensation products does not easily vary relative to variation in flow speed of the gas to be measured, and this makes equilibrium of condensation less likely to break, increasing measurement accuracy.

Abstract: An energy-autonomous sensor for detection of physical environmental parameters, having at least one sensor element, one storage element and one control circuit, with a timer circuit which is activated on reaching a predetermined electrical voltage on the storage element, activates the sensor and the control circuit at predetermined time intervals, and deactivates them after a predetermined operating time, such that this results in a time duration of sensor operation and a sensor operation pause.

Abstract: A humidity sensing apparatus and method include a substrate and a MEMS structure, wherein the MEMS structure is supported by the substrate. The MEMS structure comprises a humidity-sensitive material in association with a movable member such that when the humidity-sensitive material changes with humidity, the MEMS structure moves the movable member, thereby providing an indication of humidity based on a stress within the MEMS structure.

Abstract: An apparatus for determining the efficiency of a vaporizer in a decontamination system, having a first sensor for generating a first signal indicative of the concentration of a decontaminating chemical in a liquid decontaminate before vaporization by a vaporizer, and a second sensor for generating a second signal indicative of the concentration of vaporized decontaminate after vaporization by said vaporizer, and means for determining efficiency in accordance with said first and second signal.

Abstract: A process is provided for determining the amount of sulfuryl fluoride in the atmosphere of an enclosed area that has been fumigated with sulfuryl fluoride (SO2F2). This process comprises: (A) sampling said atmosphere of said enclosed area to obtain a gaseous sample; (B) selectively removing water from said gaseous sample by passing said gaseous sample through a perevaporation zone to obtain a perevaporated sample, wherein said perevaporation zone comprises a copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid; and (C) analyzing said perevaporated sample in a sulfuryl fluoride detector to determine the amount of sulfuryl fluoride in said perevaporated sample.

Abstract: In a gas sensor, at least three levels of current are supplied to a heating element successively in a step-like manner for a predetermined time period. An arithmetic unit receives both-end voltages of the heating element for the respective current after elapse of the predetermined time period and calculates temperature from the both-end voltage of the heating element obtained when the lowest current flows. Then, the arithmetic unit corrects the both-end voltages of the heating element using the calculated temperature, a zero-point correction equation and a sensitivity correction equation to obtain respective standardized output values. Subsequently, the arithmetic unit calculates humidity based on the difference between the standardized output values, and corrects the standardized outputs based on the calculated humidity and humidity correction equations. By this method, the arithmetic unit calculates concentration of detection target gas.

Abstract: Apparatus and methods for characterizing atmospheric refractivity and its evolution in time and space utilizing passive radiation emission measurement devices are disclosed. Based on an instrument such as a passive microwave radiometer, ancillary meteorological measurements and other information and observations, the apparatus and methods provide useful signatures for characterizing atmospheric refractivity. The system can observe to any vector in the sky, giving directional as well as zenithal measurements of the refractivity profile, its spatial and temporal gradients, and the spatial and temporal trending of the profile and its gradients.

Abstract: A measuring device for detecting a humidity and temperature of a surface of a glass pane facing an interior of a vehicle. The measuring device includes at least one humidity sensor and at least one temperature sensor jointly arranged on the surface of the glass pane, an evaluation unit connected downstream of the humidity and temperature sensors, and a signal conversion and linking unit arranged between the humidity and temperature sensors and the evaluation unit. Further, the converting and linking unit generates a rectangular wave-shaped signal having at least two different impulse lengths, each impulse length being a measure of a detected humidity and temperature.

Abstract: The invention provides a contactless sensor device operable for sensing water vapor or a predetermined chemical vapor including a thin film, wherein the thin film includes a nanostructured sensing layer and a soft magnetic layer disposed directly adjacent to the nanostructured sensing layer. The thin film has a first mass, a first density, and a first magnetostrictive resonance frequency prior to the nanostructured sensing layer adsorbing a predetermined amount of a predetermined vapor and a second mass, a second density, and a second magnetostrictive resonance frequency subsequent to the nanostructured sensing layer adsorbing the predetermined amount of the predetermined vapor. The sensor device also includes a driving coil disposed indirectly adjacent to and at a predetermined distance from the thin film, the driving coil operable for generating an alternating-current magnetic field used to query a shift in the magnetostrictive resonance frequency of the thin film.

Abstract: A device for the selective determination of the quantity of oil mist includes an impactor (1) with a micronozzle (4) for dispensing a predetermined volume of a gas to be tested, a baffle plate (5) arranged downstream of the micronozzle (4) for depositing oil particles. A window (7) is provided on the side of the baffle plate (5) facing away from the micronozzle (4).

Abstract: An optoelectronic sensor for sensing wetting of a windshield includes a first circuit, and a radiation emitter and a radiation detector both arranged on the first circuit to emit radiation toward the windshield and to detect radiation reflected from the windshield. Beam shapers parallelize the emitted radiation toward the windshield and focus radiation reflected from the windshield toward the detector. A coupling element couples the emitted radiation into the windshield and couples the reflected radiation out of the windshield. A structural element is arranged between the lens holder and the coupling element. The structural element may have retaining elements for positioning a second circuit arranged between the lens holder and the structural element relative to the windshield. The structural element may have support elements for adjustably positioning the lens holder and thereby the beam shapers relative to the first circuit and the windshield.

Abstract: Methods and apparati for measuring entrained gas content. One of the disclosed apparatus embodiments includes a chamber and piping for process fluid, the piping including two different sectors each comprising a density and temperature gauge having a pressure gauge located upstream and a second pressure gauge located downstream, the two sectors being operatively joined together by a pressure-changing device. The pressure measurement feature may be incorporated into the combination density and temperature gauge, eliminating the need for separate pressure gauges. Data generated by this invention reduces measurement error caused by the dissolving or exsolving of gases with changes in pressure of a fluid, while providing instantaneous measurement, through apparatuses that measure system conditions at each of two pressure states within a very short period of time. For instance, in the context of continuously coating a substrate, the method of this invention comprises: a.

Abstract: An image processing system includes a lamp which emits light to a glass, an imaging device which captures light which is emitted from the lamp and reflected by the glass, and an optical filter, located between the glass and the imaging device, which transmits rays with a specific wavelength of the reflected light. A lens is provided in front of the imaging device, and a focus of the lens is adjusted to a point beyond the glass, and an image processor is provided which processes an image captured by the imaging device and detects moisture on the glass.

Abstract: An image processing system that detects foreign matter on a glass window of a vehicle and objects in front of the vehicle. The system includes an image processor, a first lamp, and a second lamp. On/off control of the first and second lamps is controlled by the image processor. Light from the first lamp is reflected from the outer sauce of the glass when raindrops are present on the outside of the glass. Light from the second lamp is reflected from the inner surface of the glass when moisture is present on the inside of the glass. Any reflected light goes through a lens and an optical filter with prescribed optical characteristics to an image device. The lens is focused to a point beyond the window so that the image processor an also detect objects in front of the vehicle.

Abstract: A sensor means is proposed to determine an interior humidity and/or an interior volume delimited by a wall, in particular, of a vehicle passenger compartment 3, and a fogging up tendency of an inner surface of the wall, in particular, of a window 5 of the vehicle passenger compartment 3, with a dew point sensor 10 having a humidity sensor element 1 and a temperature sensor 2, wherein the humidity sensor element 1 and the temperature sensor 2 a thermally coupled, and a surface temperature sensor 4, wherein the dew point sensor 10 is designed to measure the air humidity and the room temperature of the interior volume and the surface temperature sensor 4 is designed to measure the temperature of the inner surface.

Abstract: A method for quantifying droplet fluxes of a water mist spray uses different measuring apparatuses and compares the measurements of the two apparatuses with one another. One of the measuring apparatuses is an iso-kinetic sampling probe in which the air velocity of the portion of the water spray mist entering the probe is made equal to the air velocity of the water mist spray around the probe by connecting a source of vacuum to the probe. The drops of the spray entering the probe are prevented from passing out of the probe. The air velocity of the spray entering the probe is measured by an anemometer, the drops of the entering spray are collected in a reservoir, and the depth of water in the reservoir is measured by a differential pressure transducer. The output of the pressure transducer is sent to a computer that calculates the water collection rate based on the sectional area of the probe opening and the water collection rate in the reservoir.

Abstract: A humidity meter with non-contact temperature measurement capability, including a humidity meter contained at least partially in a housing and having outputs relating to measured humidity parameters including humidity and ambient temperature, an output display contained in the housing, for displaying measurements to a user, a non-contact optically-based temperature sensing device coupled to the housing, having an output related to sensed temperature, and circuitry contained in the housing for processing both the humidity meter outputs and the temperature sensing device output, and transmitting the processed output to the output display.

Abstract: Apparatus and methods for mitigating precipitation effects realized at an antenna system of an instrument such as a microwave radiometer are disclosed. One embodiment of the apparatus includes a blower mechanism that enables instrument operation even during precipitation events (rain, snow, sleet, or excessive condensation) by causing a flow of air at relatively high velocity tangentially across the antenna system. The air flow is of sufficient force to disallow contact by hydrometeors with the antenna or antenna window of the system by redirecting the path of the falling hydrometeors in flight and/or to sweep hydrometeors reaching or formed at the window from the vicinity of the window. Other mechanisms for such precipitation effects mitigation are also disclosed.

Abstract: An acoustic wave sensor apparatus is disclosed, which generally includes a piezoelectric substrate having a surface thereon. One or more interdigital transducers and a passivation layer can be formed upon the piezoelectric substrate. Additionally, an absorbent material can be formed upon the acoustic path (IDTs, electrodes, etc), such that the interdigital transducers respond to a plurality of acoustic waves propagating across the surface of the piezoelectric substrate, thereby providing data indicative of humidity in the vicinity of the piezoelectric substrate, along with the passivation layer and the interdigital transducers. Additionally, one or more heaters can be formed upon a side of the piezoelectric substrate opposite the side of the piezoelectric substrate upon which the interdigital transducers, the passivation and the absorbent material are located. The heater can be preferably configured from a material such as platinum.

Abstract: A system for the retrieval and initial conditioning of sample gas for “on line” analyzers or filling of gas sample cylinders. The preferred embodiment of the present invention contemplates a system configured to obtain a representative gas phase sample from a process gas containing entrained liquid, or a process gas which generally is highly susceptible to partial condensation of some gas phase components. The preferred embodiment of the present invention teaches an assembly including a phase separation membrane and housing configured to facilitate the removal of entrained liquid from a sample gas stream. Accuracy of the sample is enhanced, and compositional changes are avoided by first extracting a sample from the process gas followed by removal of entrained liquid it may contain, with the entrained liquid removal being conducted at the prevailing process gas pressure and temperature. Thereafter the liquid free sample may be desaturated by lowering its pressure to reduce its susceptibility to condensation.

Abstract: An automated device monitors moisture content in exterior sheathing of a building for detecting moisture intrusion into the sheathing walls. A plurality of moisture sensors are embedded in selected exterior walls of the building behind the cladding and are adapted to provide signals representative of the moisture content in the walls at each of the selected locations. A control unit is operatively connected with each of the plurality of moisture sensors for generating an alarm signal when at least one of the signals representative of the moisture content in the plurality of walls is indicative of a moisture content in excess of a predetermined threshold value.

Abstract: A method and a device for measuring humidity may be suitable for determining the relative humidity in the high-humidity range. The device includes a sensor device, as well as a circuit connected to the same. The sensor device includes a capacitive humidity-sensor element, a temperature-sensor element, and a heating element, the humidity-sensor element being heated in at least one part of the humidity-measuring range. The ambient temperature is further ascertained by the circuit, from the heating power required in the heating mode, as well as from the measured, local sensor device temperature, in order to further determine the relative humidity.

Abstract: A temperature control apparatus for a humidity sensor is provided for preventing impurities from sticking on a sensor element, while protecting the sensor element from cracking due to the humidity sensor heated by a heater in the presence of condensation, to maintain a high detection accuracy of the humidity sensor. The temperature control apparatus is configured to control the temperature of a sensor element of a humidity sensor disposed in an exhaust passage of an internal combustion engine for detecting the humidity within the exhaust passage. The temperature control apparatus comprises a heater for heating the sensor element, a temperature sensor for detecting the temperature of the sensor element, and an ECU for controlling a heating amount of the heater to bring the detected temperature of the sensor element to a first predetermined temperature during an operation of the internal combustion engine.

Abstract: A mechanical breathing aid has first and second inlets respectively connectable to a source of air and a source of oxygen. A mixing location is in gaseous communication with the first and second inlets, at which controlled amounts of air and oxygen from the respective inlets are mixed. An acoustic analyzer operates during a measurement procedure to access a moisture content value for air from the source of air, to generate acoustic velocity-related information from acoustic energy interaction with the breathing gas, and to determine therefrom an oxygen content. The analyzer operates during a calibration procedure to generate acoustic velocity-related information from acoustic energy interaction with air from the source of air, and to determine therefrom an oxygen content value for the air from which is determined a moisture content value for air.

Abstract: A system for monitoring water concentration in gaseous sample is disclosed. It is readily applicable in the synthesis of biopolymer arrays/microarrays involving the use of water-sensitive reagents. A flow cell is provided in which a capacitance sensor is placed separate from a production or synthesis environment. Sample and dry gas may be provided to the flow cell via conduits and valves or a manifold system. Dry gas, such as N2, is used to dry the sensor or simply to maintain it in a dried condition. The same gas may be used to drive an optional venturi pump to draw sample for measurement into the cell from the synthesis environment.

Abstract: A microwave oven, having a humidity sensor and a voltage detecting unit for detecting a change in an output voltage of the humidity sensor, includes: a control unit for receiving a compensated voltage according to a change in temperature supplied from the humidity sensor and a detected voltage supplied from the voltage detecting unit, and determining a cooking time based on a voltage difference between the detected voltage and the compensated voltage. With this configuration, an optimal cooking time based on a being cooked can be calculated by use of the humidity sensor, and the cooking time can be controlled in a stable manner relative to external noise or irregular changes in humidity.

Abstract: A capacitive humidity sensor includes a detection portion and a reference portion. The detection portion includes detection electrodes and a moisture sensitive film. The reference portion includes reference electrodes and a moisture permeation film as a capacitance adjusting film. The capacitive humidity sensor detects humidity by converting a capacitance difference between a capacitance of the detection electrodes and a capacitance of the reference electrodes to an electric signal by using a capacitance-voltage conversion circuit. The moisture permeation film reduces offset voltage of the capacitive humidity sensor. Thus, an offset compensation circuit or the like is not required.

Abstract: Improved control of continuous processes that handle liquids. Data generated by this invention is used to control gas contents of liquids within optimum ranges, for instance in paper coating processes and in the manufacture of food products (ketchup), personal care products (shampoo), paints, and in any industry where information on entrained and/or dissolved gases, and related parameters such as true density of and gas solubility in process liquids, is employed to optimize processing. The amount of gas in a liquid is determined by subjecting a mixture of an incompressible liquid sample and a compressible gas to three or more different equilibrium pressure states, measuring the temperature and volume of the mixture at each of the pressure states, determining the changes in volume of the mixture between at least two different pairs of pressure states, and calculating the amount of gas in the liquid sample.

Abstract: The present invention refers to a method of detecting the moisture in an apparatus for treating and preparing food, as well as to a method of treating and preparing food. In the method according to the invention, the current temperature values and speed values of the asynchronous motor driving a gas supply and circulation mechanism are compared to at least one characteristic line which is stored in a computer, and the current moisture in the gas mixture is determined from the deviation ?N of the measured speed from the speed of the stored characteristic line. The present invention also comprises an apparatus for treating and preparing food that, in particular, serves to carry out the method of determining the moisture in a gas mixture.

Abstract: A humidity sensor element for a humidity sensing device includes a rigid, p doped silicon substrate, a non-porous terminal on one side of the substrate, a porous terminal on a second side of the substrate, and a layer of polyphenylsulfone between the porous terminal and the substrate. The sensor elements displays improved linear response with humidity changes and very low hysteresis.

Abstract: Silica-based carrier impregnated with iron(III) or iron(II) salts functions as a humidity indicator giving a yellow/amber to nearly colourless colour change as the carrier humidifies.

Abstract: A dew point hygrometer for determining the dew point of a gas in which a displaceable transparent film is in contact with the gas and forms a condensation surface. The film is placed on a temperature control device controlling its temperature and an optic fiber, emits light on the film and reflected light is detected in another optic fiber, the two optical fibers being positioned at an angle with respect to the film. Condensation formed on the film changes the light transmitted by the film which is periodically displaced so that a new uncontaminated regions are exposed to the light.

Abstract: A method and apparatus are described for sensing the absolute humidity of gases where the relative humidity of gases are measured, the humidity transducer is heated, the resulting temperature measured and the absolute humidity calculated (based on the power to heat said transducer, the temperature of said transducer and the relative humidity). In further embodiments the humidity transducer may be heated to a pasteurisation temperature, to substantially kill any common pathogens present on the humidity transducer. The flow rate may be determined to estimate a more instantaneous valve of humidity. The operation of the sensor may be continually monitored for correct operation and various constructions disclosed for improving the efficiency of operation.