Abstract: A dual channel inflight ice detection system to detect ice accretion on an aircraft surface by illuminating an ice collecting surface mounted on an aircraft with linear polarized light. The backscattered light is acquired in two light conductors one with polarization sensitivity aligned to the transmitted light and the second with polarization sensitivity orthogonal to the first. The presence of ice is determined by the change in the ratio of light intensities in the two light conductors.

Abstract: A sensing system computes an amount of moisture on a surface of a substrate, such as a window of a vehicle. The sensing system includes a transmitter which produces a wave to propagate through the substrate. A receiver receives the wave which propagated through the substrate. A phase shift detection circuit measures a phase shift between signals representing the transmitted and received wave. A temperature sensor senses a temperature of the substrate. A controller, in communication with the phase shift detection circuit and the temperature sensor, calculates the amount of moisture on the surface based on the phase shift and the temperature of the substrate. A wiper motor and wiper blade may then be actuated automatically based on the amount of moisture calculated to clear the moisture on the substrate.

Abstract: Characterizing atmospheric conditions is accomplished by measuring at least one varying spectral characteristic of sound at a plurality of intervals from a sound source with the point of measurement and the sound source in relative motion and separated by altitude. The spectral characteristic of the sound at each interval is attributed to a path traveled by the sound and a plurality of simultaneous equations is created for the plurality of paths using a second plurality of altitude segments for each path, each segment having a particular vector as a variable on the spectral characteristic, the initial coefficients in each vector assumed based on predetermined atmospheric models for each altitude segment. The resulting calculated vector and the predetermined atmospheric model are iterated for a minimized cost function in a variational analysis to determine the vector for each altitude segment, the vector providing atmospheric properties for the associated altitude segment.

Abstract: A precipitation measurement device measures a precipitation rate of falling precipitation. A first probe is exposed to the falling precipitation. A first temperature sensor detects a first probe temperature. A second probe is shielded from the falling precipitation. A second temperature sensor detects a second probe temperature. A heating element heats the first probe and the second probe when turned on, but not when turned off. After being heated and when the heating element is turned off, the first probe cools at a first temperature drop rate, and the second probe cools at a second temperature drop rate. Circuitry processes a difference between the first temperature drop rate and the second temperature drop rate to determine the precipitation rate of the falling precipitation.

Abstract: Disclosed is a runoff rain gauge 100 which includes a collector tube 104, soil infiltration resistance medium 108, a runoff resistance flow element 113, a standard rain gauge 102, and runoff collection tube 114. Precipitation enters the collector tube 104 and is divided to flow into the infiltration medium 108 and runoff collection tube 114 via flow element 113. Total precipitation is read in standard rain gauge 102, runoff in tube 114, and soil infiltration in medium 108 is calculated by the difference between total precipitation and the runoff. Also disclosed are a runoff rain gauge 100 comprising: a seal leg 150 downstream from the runoff resistance flow element 113; a collector tube 104 mounted directly to the ground so that the bottom of the soil infiltration resistance medium 108 contacts the ground surface; and/or a horizontal capillary tube in the runoff resistance flow element 113 to insure self-sealing via capillary forces.

Abstract: This publication discloses a method and apparatus for measuring hydrometeors. According to the method, the mechanical impulses of hydrometers falling on a detection surface are measured. According to the invention, part of the measuring device (1) is used to perform a continuous measurement, in order to define a threshold value for an impulse and only after the threshold value is exceeded is the final part (2) of the measuring apparatus excited for measuring operations, in order to minimize the power consumption of the apparatus.

Abstract: The invention relates to a precipitation detector (1) and method for measurement of precipitation parameters. The detector (1) includes a frame (5), a surface (2) mounted on the frame (5) and adapted to receive hydrometeors, and detection means (3) for converting the impact impulses of hydrometeors into an electric signal. According to the invention, the surface (2) receiving the impact of the hydrometeors is convex, stiff and rigidly connected to the detector frame (4) with the detection means (3) being permanently connected to the surface (2) receiving the impact of the hydrometeors.

Abstract: A precipitation gauge including a clear elongated outer cylinder and an opaque or translucent inner member disposed longitudinally in the outer cylinder to define a tubular water receiver in the space between the cylinder and the inner member and markings disposed along either the outer cylinder or the inner member, the gauge indicating the amount of water collected in the water receiver with a sharp demarcation at the top surface of the water resulting from an optical illusion making it appear that the portion of the gauge below the demarcation is filled with a fluid of the color of the inner member.

Abstract: An illuminated rain gauge comprising an elongated, transparent collection vessel or tube having upper and lower ends with the lower end thereof being closed by a plug and which has a funnel-shaped collector at the upper end thereof. A support is positioned within the funnel-shaped collector and has a solar collector or panel mounted thereon. A light source such as an LED is positioned on the underside of the support and is powered by the solar panel. The LED directs light into the collection vessel so that the rainfall amounts may be determined during periods of darkness. The illuminated rain gauge may take many forms and/or shapes. In one embodiment, the light source is battery powered. In another embodiment, the light source is battery powered and wireless controlled.

Abstract: Rain sensor arrangement for an operator for a window, said window comprising a frame, a sash pivotable with respect to said frame, and a pane mounted in said sash. The operator is adapted for pivoting said sash between a closed and an open position and vice versa, and said operator is controlled via a control circuitry responsive to input signals from at least a rain sensor. The rain sensor has at least one sensing area arranged so as to be protected against rain by said window, when the sash is in the closed position.

Abstract: A method is provided for determining the depth to the saturated soil at a selected site. A first and second instance wherein the depth of the water table equals the depth to the saturated soil is identified (142). The rate of change of the depth to the saturated soil is calculated (146) as a function of the specific yield, amount of time between the instances, total precipitation occurring between the instances, and depth of the water table at each instance. Then, the depth to the saturated soil for a third instance is calculated (148) as a function of the rate of change of the depth to the saturated soil. The calculated depth to the saturated soil for a third instance may be adjusted as a function of precipitation occurring at the site.

Abstract: Disclosed is a runoff rain gauge 100 which includes a collector tube 104, soil infiltration resistance medium 108, a runoff resistance flow element 113, a standard rain gauge 102, and runoff collection tube 114. Precipitation enters the collector tube 104 and is divided to flow into the infiltration medium 108 and runoff collection tube 114 via flow element 113. Total precipitation is read in standard rain gauge 102, runoff in tube 114, and soil infiltration in medium 108 is calculated by the difference between total precipitation and the runoff.

Abstract: A sensor support includes a rigid insert, on which a sensor is installed, and a flexible envelope fitted at a bottom face thereof with a double-sided adhesive to bond the sensor support to an aircraft structure Assembly and disassembly of the sensor are easy and the air flow is only slightly disturbed. This device is applicable to flight test campaigns of an aircraft or simulated flights to measure noise or pressure.

Abstract: A vehicular rain sensor mounting system comprises a module assembly adapted for attachment to an attachment member on the inner surface of a vehicle windshield. The module assembly comprises a first side configured to be generally adjacent the inner surface of the vehicle windshield and a second side generally opposing the first side. A rearview mirror assembly mounting member is provided at the second side. The system further comprises a rearview mirror assembly having a mirror mount adapted for attachment to the rearview mirror assembly mounting member provided at the second side of the module assembly. The module assembly includes a rain sensor having a detecting surface. The detecting surface of the rain sensor contacts the inner surface of the windshield when the module assembly is attached to the attachment member on the inner surface of the vehicle windshield.

Abstract: A rain sensor and a method for installing a rain sensor are provided for a motor vehicle. The rain sensor includes a housing in which at least one printed circuit board is located and which has a light-conducting member, which at least partially closes the housing in the manner of a lid. A plate is located between the light-conducting member and the printed circuit board. During installation, the plate is partially punched through.

Abstract: A sensor for optical detection of foreign bodies, in particular raindrops, on a window, in particular on the windshield of a motor vehicle, having a sensor element that is coupled to the inside of the window and having a fastening device, which is glued to the window, wherein the housing part has a fastening part pivotably attached to it, which can be brought into engagement with the fastening device by the clamping tension.

Abstract: A method for determining a rate of rain falling on a surface. As rain falls and strikes the surface, vibrations are generated on the surface. The vibrations are sensed and a vibration signal is generated, the vibration signal being proportional to the vibrations of the surface. The vibration signal includes peaks. The peaks of the vibration signal are determined. The time intervals between the peaks are then determined. Using the time intervals, a number n1 of timer intervals that occur between a first time and a second time are counted. A number n2 of time intervals that occur between the second time and a third time are also counted. The rain rate ? is then determined using an equation that is derived from a point process equation and utilizes n1 and n2.

Abstract: A sensor-mirror arrangement on a windshield of a motor vehicle with an optical sensor that is fastened on the windshield in an edge region arranged between a free field of vision of the windshield and vehicle roof, and with an inside rearview mirror that is fastened using a mirror mounting in an upper edge region between the sensor and the vehicle roof. The mirror mounting has a first fastening element that interacts with a complementary second fastening element for fastening the inside rearview mirror, which is constructed with a mirror base of the inside rearview mirror. The mirror mounting moreover has a pedestal fastened on the windshield on its side facing away from the windshield the first fastening element is formed. The pedestal is dimensioned so that the mirror base fastened to the mirror holding has a predetermined distance from the windshield, which is greater that a minimum distance if need be required for the installation and/or function of the mirror base.

Abstract: A rain gauge assembly includes, in an exemplary embodiment, a first hollow cylinder having a side wall and a bottom wall closing a first end of the first cylinder. The first cylinder is open at a second end. The assembly also includes a second hollow cylinder having a side wall and a bottom wall closing a first end of the second cylinder. The second cylinder is open at a second end and has an inside diameter approximately equal to the outside diameter of the first cylinder so that the first cylinder is receivable in the second cylinder. The second cylinder has a length that is less than the length of the first cylinder. The first and second cylinders are molded from a resilient translucent plastisol material. The assembly further includes a means for attaching the second cylinder to a surface.

Abstract: A rain sensor (10), in particular for a motor vehicle, is shown, having at least one transmitter (20) emitting radiation in the operating state, and at least one receiver (22) at least partially sensitive to the radiation from the transmitter (20), and a substantially flat light-conducting body (14) that is capable of being coupled nearly parallel to a surface of a wettable window pane (12) of the motor vehicle, and comprising structures (18a, 18b) for directing and catching the radiation from the transmitter (20), whereby the structures (18a) for directing the radiation are different from the structures (18b) for catching the radiation, and they have radiation-concentrating properties.

Abstract: A precipitation measuring system comprising a top thermal plate positioned to maximize exposure to falling precipitation and includes at least one ridge circumscribing the top surface for capturing precipitation. A second thermal plate is positioned under the top thermal plate to protect it from falling precipitation while still exposing it to the same atmospheric temperature and wind conditions. At least one solar radiation sensor is connected to the precipitation measuring system to measure solar radiation contacting at least one of the top and bottom thermal plates. During a precipitation event, the top and bottom thermal plates are maintained at a constant temperature and a power consumption curve for each thermal plate is quantified. The precipitation rate is measured by the difference in the power consumption curve for the top thermal plate and the power consumption curve for the bottom thermal plate.

Abstract: A precipitation measuring system comprising a top thermal plate positioned to maximize exposure to falling precipitation and includes at least one ridge circumscribing the top surface for capturing precipitation. A second thermal plate is positioned under the top thermal plate to protect it from falling precipitation while still exposing it to the same atmospheric temperature and wind conditions. At least one solar radiation sensor is connected to the precipitation measuring system to measure solar radiation contacting at least one of the top and bottom thermal plates. During a precipitation event, the top and bottom thermal plates are maintained at a constant temperature and a power consumption curve for each thermal plate is quantified. The precipitation rate is measured by the difference in the power consumption curve for the top thermal plate and the power consumption curve for the bottom thermal plate.

Abstract: A precipitation measuring system comprising a top thermal plate positioned to maximize exposure to falling precipitation and includes at least one ridge circumscribing the top surface for capturing precipitation. A second thermal plate is positioned under the top thermal plate to protect it from falling precipitation while still exposing it to the same atmospheric temperature and wind conditions. At least one solar radiation sensor is connected to the precipitation measuring system to measure solar radiation contacting at least one of the top and bottom thermal plates. During a precipitation event, the top and bottom thermal plates are maintained at a constant temperature and a power consumption curve for each thermal plate is quantified. The precipitation rate is measured by the difference in the power consumption curve for the top thermal plate and the power consumption curve for the bottom thermal plate.

Abstract: A precipitation measuring system comprising a top thermal plate positioned to maximize exposure to falling precipitation and includes at least one ridge circumscribing the top surface for capturing precipitation. A second thermal plate is positioned under the top thermal plate to protect it from falling precipitation while still exposing it to the same atmospheric temperature and wind conditions. At least one solar radiation sensor is connected to the precipitation measuring system to measure solar radiation contacting at least one of the top and bottom thermal plates. During a precipitation event, the top and bottom thermal plates are maintained at a constant temperature and a power consumption curve for each thermal plate is quantified. The precipitation rate is measured by the difference in the power consumption curve for the top thermal plate and the power consumption curve for the bottom thermal plate.

Abstract: A rain sensor and a method for installing a rain sensor are provided for a motor vehicle. The rain sensor includes a housing in which at least one printed circuit board is located and which has a light-conducting member, which at least partially closes the housing in the manner of a lid. A plate is located between the light-conducting member and the printed circuit board. During installation, the plate is partially punched through.

Abstract: A precipitation measuring system comprising a top thermal plate positioned to maximize exposure to falling precipitation and includes at least one ridge circumscribing the top surface for capturing precipitation. A second thermal plate is positioned under the top thermal plate to protect it from falling precipitation while still exposing it to the same atmospheric temperature and wind conditions. At least one solar radiation sensor is connected to the precipitation measuring system to measure solar radiation contacting at least one of the top and bottom thermal plates. During a precipitation event, the top and bottom thermal plates are maintained at a constant temperature and a power consumption curve for each thermal plate is quantified. The precipitation rate is measured by the difference in the power consumption curve for the top thermal plate and the power consumption curve for the bottom thermal plate.

Abstract: A window fan assembly comprising a housing with openings therein for an air stream through the housing; at least one fan is mounted in the housing for generating the air stream through the openings of the housing; and a sensor connected to the housing, the sensor being disposed on the housing for detecting moisture particles associated with the air stream, upon the detection of a moisture particle of a predetermined size, the sensor causes an interruption of the air stream by stopping the fan operation.

Abstract: A rain sensor to detect humidity drops inside an area on a transparent window has at least one transmitting element to emit optical rays into the window and has at least one receiving element to receive at least one part of the emitted optical rays where the intensity of the optical rays received is dependent on the number of humidity drops in the area of the window observed by the rain sensor. So that interference from the rain sensor with radio broadcasts is effectively reduced and, if possible even completely prevented, the rain sensor has a generator to generate an electrical signal which has a lower harmonic content than square-wave signals, preferably a sine-wave electrical signal to power each transmitting element of the rain sensor.

Abstract: The present invention provides an object-sensing device capable of estimating the presence of an object attached on a sensing surface, the kind of the object and the state of the object. An image is formed by a lens with light via the sensing surface, and the light is received by a light-receiving element portion in which a plurality of micro-light-receiving elements are arranged. In the object detection mode, totally reflected light from the sensing surface is received by the light-receiving element portion. The components are arranged at an angle that allows total reflection when there is no object, and does not allow the total reflection condition to be satisfied when there is an object. In the light scattering object detection mode, scattered light from the sensing surface is received by the light-receiving element portion. A signal pattern is obtained by joining detection signal levels of the micro-light-receiving elements in accordance with the arrangement of the micro-light-receiving elements.

Abstract: A moisture sensing device for detecting moisture on a moisture collecting surface including an air pump for accelerating the formation of moisture on the moisture collecting surface. The moisture sensing device includes a moisture sensor that is operably positionable relative to a moisture collecting surface. The device also includes an air pump for accelerating the formation of moisture on the moisture collecting surface. A small pump can direct a flow of air over the moisture collecting surface to accelerate the formation of moisture through condensation.

Abstract: A moisture detection system includes an electrical conductor disposed on a surface of a substrate. The electrical conductor has a resonant frequency that varies as a function of an amount of moisture present adjacent the electrical conductor. An oscillator outputs an oscillator signal at a predetermined amplitude and a predetermined frequency. A resonator circuit is coupled to the electrical conductor and is responsive to the oscillator signal and the resonant frequency of the electrical conductor for outputting a resonator signal having an amplitude related to the resonant frequency of the electrical conductor. A filter circuit rectifies and filters the resonator signal and provides it to an analog-to-digital converter which outputs a digital signal related to the rectified and filtered resonator signal. A controller is responsive to the digital signal for causing a system associated with the substrate to operate in accordance with the digital signal.

Abstract: A mount for mounting a rain sensor includes a housing having an access opening on first side and a port on second side for positioning adjacent an inner surface of the vehicle windshield. The second side is adapted for mounting to a vehicle windshield, for example by a layer of adhesive which is interposed between the housing and the windshield. Optionally, the housing includes an access opening and a cover, which and covers the access opening. A mirror mounting button is provided on either the housing or the cover for mounting a rearview mirror assembly to the mount. A biasing member is supported in the housing and is interposed between the first side of the housing and a rain sensor positioned in the housing, which urges a detecting surface of the rain sensor to project through the port and to optically couple the rain sensor to the vehicle windshield for detecting moisture on an outer surface of the vehicle windshield. The biasing member may comprise, for example, a helical spring or a urethane disc.

Abstract: The invention concerns dew point hygrometers based on condensation of dew on ends of optical fibers, or on surfaces of an optical prism. The invention also concerns a dew sensor for determining the natural dew condensation by optical means and a dew sensor capable of detecting dew by detecting a change in capacitance.

Abstract: A rain sensor (10), in particular for a motor vehicle, is shown, having at least one transmitter (20) emitting radiation in the operating state, and at least one receiver (22) at least partially sensitive to the radiation from the transmitter (20), and a substantially flat light-conducting body (14) that is capable of being coupled nearly parallel to a surface of a wettable window pane (12) of the motor vehicle, and comprising structures (18a, 18b) for directing and catching the radiation from the transmitter (20), whereby the structures (18a) for directing the radiation are different from the structures (18b) for catching the radiation, and they have radiation-concentrating properties.

Abstract: A precipitation measuring system comprising a top thermal plate positioned to maximize exposure to falling precipitation and includes at least one ridge circumscribing the top surface for capturing precipitation. A second thermal plate is positioned under the top thermal plate to protect it from falling precipitation while still exposing it to the same atmospheric temperature and wind conditions. At least one solar radiation sensor is connected to the precipitation measuring system to measure solar radiation contacting at least one of the top and bottom thermal plates. During a precipitation event, the top and bottom thermal plates are maintained at a constant temperature and a power consumption curve for each thermal plate is quantified. The precipitation rate is measured by the difference in the power consumption curve for the top thermal plate and the power consumption curve for the bottom thermal plate.

Abstract: The invention is a rain sensor including a transmitter and receiver formed by chips bonded onto a printed circuit board. Advantageous embodiments of the invention provide filtering of radiation guided to the receiver of the sensor. The sensor is provided with a barrier to suppress parasitic radiation.

Abstract: A rain sensor includes an amplifier circuit that amplifies an output voltage from a photodiode and then provides this voltage signal to a CPU. The amplifier circuit conducts an offset amplification. The output voltage from the amplifier circuit is controlled to be at a predetermined level, for example, 3.0V, and the CPU detects rainfall based on the drop in the output voltage from the predetermined level, 3.0V. Then it becomes possible to improve sensor sensitivity, maintain a small sensor size, and a low manufacturing cost.

Abstract: A module assembly suitable for attachment to an inner surface of a vehicle windshield includes a housing and a rain sensor. The housing comprises a first side, which is configured to be generally adjacent the inner surface of the vehicle windshield when the module assembly is attached to the inner surface of the windshield. The housing further comprises a second side, which is generally opposing the first side. The module assembly further includes a rearview mirror assembly mounting member provided at the second side of the housing for releasably mounting a rearview mirror assembly to the module assembly. The rain sensor and at least one other vehicular accessory are accommodated in the housing, which is adapted at its first side for attachment to the inner surface of the vehicle windshield by at least one of a mechanical attachment and an adhesive attachment.

Abstract: A predicting system configured to predict an inflow volume of rainwater includes a rainfall volume measuring unit for measuring a rainfall volume that has fallen by a present time, a rainfall volume predicting unit for predicting a rainfall volume in a future, and an inflow-volume measuring unit for measuring an inflow volume of rainwater that has flown into an objective facility by the present time. The system also includes a model identification unit, which has a non-linear model having a Neural-Network model for calculating an inflow volume of rainwater from a rainfall volume, and which has a parameter determining part for determining a degree and coefficient parameters of the non-linear model, based on the rainfall volume that has fallen by the present time measured by the rainfall volume measuring unit and the inflow volume of rainwater that has flown into the objective facility by the present time measured by the inflow-volume measuring unit.

Abstract: A moisture sensing device for detecting moisture on a moisture collecting surface including an air pump for accelerating the formation of moisture on the moisture collecting surface. The moisture sensing device includes a moisture sensor that is operably positionable relative to a moisture collecting surface. The device also includes an air pump for accelerating the formation of moisture on the moisture collecting surface. A small pump can direct a flow of air over the moisture collecting surface to accelerate the formation of moisture through condensation.

Abstract: A mount for mounting a rain sensor includes a housing having an access opening on first side and a port on second side for positioning adjacent an inner surface of the vehicle windshield. The second side is adapted for mounting to a vehicle windshield, for example by a layer of adhesive which is interposed between the housing and the windshield. Optionally, the housing includes an access opening and a cover, which and covers the access opening. A mirror mounting button is provided on either the housing or the cover for mounting a rearview mirror assembly to the mount. A biasing member is supported in the housing and is interposed between the first side of the housing and a rain sensor positioned in the housing, which urges a detecting surface of the rain sensor to project through the port and to optically couple the rain sensor to the vehicle windshield for detecting moisture on an outer surface of the vehicle windshield. The biasing member may comprise, for example, a helical spring or a urethane disc.

Abstract: A rain gauge assembly has a collection cylinder situated within a vertical support housing. The lowermost portion of the collection cylinder comes to a point which rests upon the bottommost surface of the support housing. The uppermost portion of the collection cylinder is supported by the uppermost portion of the support housing. Connected to the uppermost portion of the collection cylinder is a flexible connector which is connected to a collector and a collector funnel. Affixed to the collector is a wind deflector support arm. The wind deflector support arm is attached to a vertical deflecting fin and a horizontal deflecting fin. The vertical and horizontal fins are situated in perpendicular planes for reacting to both wind direction and wind velocity, respectively.

Abstract: A mount for mounting a rain sensor includes a housing having an access opening on first side and a port on second side for positioning adjacent an inner surface of the vehicle windshield. The second side is adapted for mounting to a vehicle windshield, for example by a layer of adhesive which is interposed between the housing and the windshield. Optionally, the housing includes an access opening and a cover, which and covers the access opening. A mirror mounting button is provided on either the housing or the cover for mounting a rearview mirror assembly to the mount. A biasing member is supported in the housing and is interposed between the first side of the housing and a rain sensor positioned in the housing, which urges a detecting surface of the rain sensor to project through the port and to optically couple the rain sensor to the vehicle windshield for detecting moisture on an outer surface of the vehicle windshield. The biasing member may comprise, for example, a helical spring or a urethane disc.

Abstract: An ice detector for an aircraft comprises a strut and probe assembly, and it is positioned on the aircraft so that the pressure field around the ice detector causes a lower temperature region on the probe assembly compared to the aircraft. Ice will therefore form on the probe assembly before it forms on the aircraft to provide an early warning of icing conditions near freezing temperatures.

Abstract: A mount for mounting a rain sensor includes a housing having an access opening on first side and a port on second side for positioning adjacent an inner surface of the vehicle windshield. The second side is adapted for mounting to a vehicle windshield, for example by a layer of adhesive which is interposed between the housing and the windshield. Optionally, the housing includes an access opening and a cover, which and covers the access opening. A mirror mounting button is provided on either the housing or the cover for mounting a rearview mirror assembly to the mount. A biasing member is supported in the housing and is interposed between the first side of the housing and a rain sensor positioned in the housing, which urges a detecting surface of the rain sensor to project through the port and to optically couple the rain sensor to the vehicle windshield for detecting moisture on an outer surface of the vehicle windshield. The biasing member may comprise, for example, a helical spring or a urethane disc.

Abstract: A mount for mounting a rain sensor includes a housing having an access opening on first side and a port on second side for positioning adjacent an inner surface of the vehicle windshield. The second side is adapted for mounting to a vehicle windshield, for example by a layer of adhesive which is interposed between the housing and the windshield. Optionally, the housing includes an access opening and a cover, which and covers the access opening. A mirror mounting button is provided on either the housing or the cover for mounting a rearview mirror assembly to the mount. A biasing member is supported in the housing and is interposed between the first side of the housing and a rain sensor positioned in the housing, which urges a detecting surface of the rain sensor to project through the port and to optically couple the rain sensor to the vehicle windshield for detecting moisture on an outer surface of the vehicle windshield. The biasing member may comprise, for example, a helical spring or a urethane disc.

Abstract: An ice detector for an aircraft comprises a strut and probe assembly, and it is positioned on the aircraft so that the pressure field around the ice detector causes a lower temperature region on the probe assembly compared to the aircraft. Ice will therefore form on the probe assembly before it forms on the aircraft to provide an early warning of icing conditions near freezing temperatures.