Abstract: A sensor for detecting moisture on a non-conductive support, in particular a windshield of a motor vehicle, has one or more metallic, electrically conductive layers which are arranged in a given pattern on the outer surface of the support. The metallic, electrically conductive layer is produced from a metallic resinate which is applied to the support and then burned-in by the action of heat. Also deseribed is a method for constructing such a moisture sensor whit applies a glass layer in the form of a glass frit paste to be sintered upon the metallic electrically conductive layer, where the burning-in of the metallic resinate and the sintering of the glass frit paste are effected in single step.

Abstract: A rain sensor for the windshield of a vehicle has one or more electrically conductive layers which are arranged in a given pattern upon the outer surface of such windshield, and is constructed as a laminate of conductive and resistive layers formed by process steps of printing and sintering for construction of electrodes of the sensor. A conductive layer is formed of a mixture of electrically conductive particles and a glass frit which melts at a lower temperature than a melting temperature of the material of the window which serves as a support for the sensor. The conductive paste is applied with a heating action step, in the configuration of an electrode structure, by sintering to the window.

Abstract: Ceiling tiles and a moisture detection system in which an array of electrodes placed preferably on the top unseen surface of the ceiling tiles typically used in commercial-type buildings. A detection or controller circuit then monitors the electrical characteristics of these electrodes for any changes that would be indicative of water formation on the ceiling tiles. Generally, current will flow between the electrodes only in the presence of water or some other conducting fluid. When this current is detected, an alarm, for example, can be generated to notify security monitoring personnel to investigate the possible existence of water intrusion. Alternatively, coded signals can be generated at the ceiling tiles individually in the presence of water.

Abstract: A system for detecting the presence of rain droplets on a windshield employs a source of light, such as an LED, and a photodetector installed on the instrument panel of a vehicle. The LED and the photodiode are arranged with respect to one another such that light from the LED cannot reflect directly off the windshield into the photodiode. Only when the light from the LED is backscattered by an environmental condition, such as the raindrops on the exterior of the windshield, the condensation of moisture on the interior of the windshield, or the presence of smoke in the cabin, will the photodiode receive the light from the LED. Each of these environmental conditions has a predeterminable characteristic signature which permits the processing of data to detect same.

Abstract: A process and a system for controlling a windshield wiper, in particular on a motor vehicle, employs a sensor which recognizes the intensity of the rain. The sensor gives off a signal whereby the windshield wiper is automatically controlled as a function of the intensity of the rain. A variation in the signal of the sensor is effected by random signals produced by the continuous movements of drops of water, and serves as measure for the intensity of the rain. In order to assure an optimal and reliable control of the windshield wiper as a function of the intensity of the rain, there is a monitoring of the time between a first sudden change of the signal and a second sudden change. When the time exceeds a given value, the windshield wiper is controlled as a function of at least an earlier one of the sudden changes in the sensor signal which precedes the aforementioned first sudden change.

Abstract: In a wetness sensor for a window of a motor vehicle, a heating resistor arranged in the window and powered by DC current can be connected to a measuring device for measuring an AC impedance of the heating resistor, in particular the capacitive portion thereof. The impedance varies with the amount of wetness and, thereby, serves as a measure of the wetness. A capacitor is used to bring the sensor near resonance for improved sensitivity.

Abstract: An improved visibility detector and method emit infrared radiation away from an infrared emitter; detect an amount of infrared radiation backscattered by an airborne visibility impeding agent; and generate a backscatter signal in response to the amount detected. In one embodiment, the detector detects an amount of the infrared radiation that is not backscattered; generates a reference signal in response thereto; determines an actual amount of the infrared radiation backscattered; determines whether the actual amount exceeds a prescribed threshold; and generates an alarm signal in event the actual amount is determined to exceed the prescribed threshold.

Abstract: A rain sensor having two non-contacting conductive paths which are aligned parallel to each other and are arranged on the windshield of a motor vehicle, with an evaluation electronics system connected to them. In order to create a rain sensor having the smallest possible dimensions, the width of at least one conductive path is made non-constant over its length.

Abstract: An optoelectronic sensor device which has a beam transmitter/beam receiver arrangement associated with a beam guide element. The arrangement is disposed together with a heating device in a common housing. In order to install the heating device in a convenient manner in the surrounding area of the sensor device, the heating device consists of at least one heat conducting plate fixed to a support part, which is allocated with its substantial main areas to the beam guide element and is connected by at least one connection arm to the electrical printed circuit board. The heating device includes at least one heating element, which is disposed in the proximity of a connection arm directly on the electrical printed circuit board. For communicating the necessary heat into the heat conducting plate, the printed circuit board is connected at least in a material-locking manner to an associated connection arm.

Abstract: A rain sensor which is arranged on the outside of the windshield of a motor vehicle in a region which can be passed over by a windshield wiper and has at least one conductive track which is connected to an electric potential within the motor vehicle. A loop resistance of the conductive track (1, 2) is measured for the electrical detection of a tear.

Abstract: A process and a system for controlling a windshield wiper, in particular on a motor vehicle, in which a rain sensor is located on the glass to be wiped and within the region of the windshield wiper. The sensor outputs a sensor signal as a function of the amount of moisture. The signal is detected periodically and, when a reference degree of moisture is reached during a measurement cycle, the system produces a triggering signal and the windshield wiper is activated. The wiping process takes place even when the windshield wiper is wetted with moisture only to a slight but nevertheless disturbing extent. In the process, when a degree of moisture below a reference degree of moisture is present at the end of the measurement cycle, this degree of moisture is included additively to the degree of moisture of a further measurement cycle. Thereupon, the degree of moisture of the further measurement cycle is compared with the reference degree of moisture.

Abstract: A device and method for containing spills and leaks from fuel handling equipment is provided in which differential sensing means detect the presence of hydrocarbons and nonhydrocarbons such as water. Signals and the responses generated according to them may depend upon the nature and quantity of the substance contained in the device. Signalling may be conducted remotely and excavation and reconstruction of service station grounds is minimized with these devices. In a preferred embodiment, the device is made of unitary construction with the differential sensing means formed as a portion of the surface of a containment vessel.

Abstract: An early warning tornado detector is provided. The detector utilizes a plurality of horizontally rotatable negative ion flow meters, each of said meters capable of taking measurements of negative ion flow in a linear direction. Means for recording said measurements are provided, as are means for determining the negative ion flow intensity for a fixed location by correlating the linear measurements corresponding to that location taken from at least two of said meters. Also provided is a method for early detection and tracking of meteorological conditions conducive to tornado formation in a given area. In this method the negative ion flow intensity threshold level which indicates that meteorological conditions are conducive to tornado formation in the area is first determined. Then, the negative ion flow intensity over the area is measured. By comparing the measured ion flow intensity with the threshold intensity, it can be determined if tornado formation is imminent.

Abstract: A microsensor system for determining water vapor content of the ambient atmosphere that uses a thin film suspended ceramic diaphragm structure featuring an embedded, patterned thin film heater, temperature sensor and an external film of an hygroscopic salt stabilized in a water-insoluble, crosslinked polymer matrix and contacting a pair of patterned electrodes which are proximate to the heater. The heater controls a selected electrical parameter of the salt to a fixed, predetermined value, as determined by its electrical characteristics. The dew point of the atmosphere is determined based on the dynamic relation with the salt dehydration temperature.

Abstract: An electrical rain sensor to be mounted on the outside of a main frame of an openable window, particularly a skylight, comprising a sensing element with two electrodes mounted opposite one another in an insulating holder, the distance between the electrodes being less than the size of a raindrop. To the electrodes an electric circuit is connected which by detection of a change in an electrical quantity caused by the presence of raindrops, activates a maneuvering device which closes the window. The holder (8) is produced by molding of an electrically insulating thermoplastic, wherein the supply lines to the electrodes (15, 16) as well as a heating element for the drying of the sensor are produced as inserts in the holder by molding of an electrically conductive thermoplastic polymer into excavated recesses and/or grooves in the holder (8).

Abstract: A road surface condition detector for detecting a dry/wet condition of a road surface includes an ultrasonic wave receiver 2 for picking up the ultrasonic noise generated by a road wheel tire 1, which increases conspicuously when the R is wet. The output of the ultrasonic wave receiver 2 is amplified by a amplifier 21, and the absolute level thereof is detected by an absolute level detector 22, and the absolute level is smoothed by a received-wave intensity detector 20. The smoothed signal is compared with a reference voltage Vt to determine the road surface condition. Preferably, the reference voltage Vt is varied in accordance with the vehicle speed. When the automotive vehicle is provided with ultrasonic wave transmitter/receiver units 3a and 3b, the ultrasonic noise component is extracted from the received signal by an ultrasonic noise intensity detector circuit 40, and the extracted component is compared with a reference voltage level to determine the road surface condition.

Abstract: In a method for detecting a hydroplaning risk for vehicle tires the sequential deformations of tread elements of the vehicle tire in the circumferential direction during contacting the road surface are measured. A sequence of corresponding signals is generated. The sequence of corresponding signals is processed to produce processed signals. The processed signals are compared to predetermined evaluation standards, and a warning signal for indicating the imminent danger of hydroplaning is sent as a function of the predetermined standards.

Abstract: A detector circuit in a moisture detector having an oscillator, a detector electrode and a common electrode for measuring the moisture content of wood and structural materials in buildings comprises a clamping diode network which couples an AC signal generated in the oscillator to a detector electrode. The clamping network clamps the AC signal to a reference voltage. The clamping network is balanced by a second clamping diode network which, together with a low pass filter, establishes the reference voltage. A low pass filter connected to the first clamping network produces an output voltage signal related to the impedance between the electrodes. To maintain the circuit's stability, the diodes in the clamping networks are thermally coupled.

Abstract: A device for attaching to and detecting wetness in diapers. The device including a pair of probes (28) supported on a module box (10) slidably mounted between the guides (36) of a slide section (34). The device is attachable to the diaper (56) by sliding the module box (10) toward the slide section (34) such as to trap a fold of the fabric item between the probes (28) and the slide section (34). The module box (10) contains a signal circuit (14) which is activated when wetness is present between the probes (28) in the fold of the fabric item. The signal can be a melody playing IC chip or LCD time display, or both.

Abstract: A moisture sensor with two heatable concentric moisture electrodes and a temperature sensor detecting the electrode temperature is set into the roadway surface to be monitored. The moisture electrodes are heated by a heating current circuit. The heating current circuit is connected to a computer which has a store for storing device-specific parameters, desired values and a processing program. During each measuring cycle the computer processes the temperatures of the moisture electrodes measured by the temperature sensor and a signal which is representative of the surface moisture. A control signal is produced therefrom which heats the moisture electrodes. An alarm or switching signal is produced when the moisture electrodes have reached a temperature characteristic of the formation of ice and a conductivity indicative of moisture is present between the moisture electrodes.

Abstract: A capacitive moisture sensor includes insulator means; capacitance means including a sensing capacitor having a plurality of spaced capacitive sensor conductors mounted with the insulator means for exposure to the atmosphere; and first and second electrodes mounted with the insulator means remote from the spaced capacitive sensor conductors; means for applying a periodic input current across the first and second electrodes; and means for detecting a change in capacitance between the first and second electrodes indicative of moisture bridging at least two of the capacitive sensor conductors.

Abstract: In an automobile multiplex data communication system (1000), a fail-safe function is established without providing a specific function switch. The automobile multiplex data communication system (1000) includes: transmission means (3:11:101:901) for transmitting operation data about a plurality of operation units (2a:106:204:704) provided with a plurality of terminal units (1a:202:602:902) corresponding thereto, which are required to operate an automobile; drive means (4:420) for driving a relevant terminal unit (1a:202:602:902) in response to said operation data; detecting means (5:410) for detecting an extraordinary state concerning transmission/reception operations of said operation data to produce an extraordinary-state detection signal; and control means (6:12) for independently controlling the operation of said relevant terminal unit (1a:202:602:902) by AND-gating said extraordinary-state detection signal and each of operation outputs derived from said operation units.

Abstract: Disclosed in a Rainfall Detection and Disable Control System which provides detection and a visual display of both a trace level and a variable accumulation level of natural rainfall. The dual interacting rainfall detection system provides a unique sprinkler system control function that disables sprinkler system watering both during and after a rain shower, based upon the amount of rainfall accumulation, and user selectable disable time periods. A short variable disable time period is initiated by the trace rainfall detection probe and a long variable time period is initiated by the accumulation rainfall detection probe. The trace rainfall detection probe provides the control function of preventing watering, at the onset of, and during a rain shower. The short disable time period of the trace detection function allows the next watering cycle to occur, if no significant rainfall accumulation is detected.

Abstract: A warning system for detecting pre-flight aircraft icing employs parameter sensing means located at a plurality of locations along an aircraft structure, each of said sensing means positioned to sense an outer skin temperature of the aircraft structure at each of said locations and producing signals indicative thereof. Signal averaging means average said signals produced by said sensing means to produce signals representative of the average value of the outer skin temperature in a predefined area. Relative humidity sensing means produce a signal representative of the ambient relative humidity surrounding the aircraft structure prior to takeoff. Comparing means compare the outputs of said averaging means and said humidity sensing means with predetermined values of same defining an icing susceptibility region and produce a signal when the value of the sensed parameters falls within said region.

Abstract: A device for providing a signal emulating the wetness of plant leaves, includes a first generally horizontal surface; a second, generally upwardly facing sloped surface having an edge spaced above the first surface by a gap, so that drops of moisture can accumulate on the second surface, and run off the edge, bridging the gap, and first and second leads extending from the first and second surfaces, respectively, to measure the conductivity/resistivity across the gap. Also disclosed is a method of providing a signal emulating the wetness of plant leaves including the steps of: providing a first generally horizontal surface; providing a second, generally upwardly facing sloped surface having an edge spaced above the first surface by a gap, so that drops of moisture can accumulate on the second surface, and run off the edge, bridging the gap between the first and second surfaces; and measuring the conductivity/resistivity across the gap between the first and second surfaces.

Abstract: A moisture-sensing device for automatically closing motor vehicle external openings such as convertible tops, sun or moon roofs, or windows; a moisture sensor for providing a signal by as little as a single drop of water; a device providing for closing any combination of external openings simultaneously (or sequentially); a device providing for the closing of a sun or moon roof that possesses a safety feature requiring two separate closure steps; a device providing for a signal to a hand-held beeper to alert a person to close a manually operated vehicle opening.

Abstract: An optical device is provided for detecting the degree of obscuring moisture or precipitation on the windshield of an automotive vehicle. A source of light, such as a light emitting diode (LED) or a laser diode, is positioned to illuminate the windshield. An optical imager and detector array senses light emitted by the source, either transmitted or reflected by the windshield, and imaged on the array. The light source and detector may be positioned in convenient, out-of-the-way locations inside or outside the windshield. When the windshield is free of obscuring precipitation, light from the source is imaged on a sensor of the array aligned with the optical axis of the imager. When obscuring moisture or precipitation is present on the windshield, light is scattered such that significant portions are imaged on sensors off the optical axis of the imager.

Abstract: The apparatus which predicts the onset of thunderstorm and the occurrence of close thunderbolts, includes a composite sensor with several metal pipes radially installed with equal separation on a hemispherical electrode. A plurality of corona needles are provided on the insulator at the end of each metal pipes, and the needles are electrically connected together within the composite sensor. The hemispherical electrode is connected to a circuit that counts the number of electric field-changes for certain time intervals. In case the receiving frequency exceeds the pre-determined level, it issues a first alarm. The groups of corona needles are connected to the circuit that measures the corona current, and issues a second alarm, in case the current a pre-determined level. In addition, the circuit includes circuitry that picks up the large amplitude corona current changes that the polarity change and issues the thunderbolt warning.

Abstract: The invention provides a monitor for monitoring the condition of fibre optic communication cables. The system employs one or more of the optical fibres of a cable to monitor the cable structure for damage or kinks. By using two separate laser sources and simultaneously monitoring the optical losses at two distinct and separate wavelengths, the loss signature of the monitored fibre is determined, analyzed and related to the mechanical condition of the cable structure. To monitor splice points for moisture, a special optical splice sensor unit detects any penetration of water into the splice and transmits a coded alarm signal over the monitored fibre to the optical receiver. Every splice location is assigned a unique sensor code. The optical splice sensor is driven by moisture detection cell, which forms a single cell water activated battery. Water entering the monitored splice closure wets the tape, which activates the cell.

Abstract: A compressed air system includes an air dryer which includes a desiccant for drying compressed air passed through the desiccant before the compressed air is received in a storage reservoir. A humidity sensor is installed in the system downstream of the desiccant for measuring the relatively humidity of the air after it passes through the air dryer. A control module is programmed such that if the humidity level increases above 80%, a timer is started. If a time period of several hours elapses without the humidity level decreasing below 50%, a depleted desiccant and/or a system malfunction is indicated, and an appropriate warning device is actuated.

Abstract: A portable air quality indication unit senses and indicates at least the ambient concentration of aerosols and particulates, the ambient concentration of a gas such as CO, the ambient temperature and the relative humidity, and displays the same. The gas concentration level and particulates concentration level are provided as good or satisfactory, bad or unsatisfactory, or fair/good, i.e., marginal depending on the relation of the detected level to the predetermined threshold level values of gas concentration, and particulates concentration. Temperature and relative humidity can be displayed on liquid crystal displays. A microprocessor circuit within the unit assumes a low-power standby mode, in which the gas and particulates sensor means are sampled at a relatively low rate, when the particulates level and gas concentration level are below their respective TLVs.

Abstract: A circuit arrangement for detecting foreign bodies on a transparent element, particularly in a motor vehicle, including a dynamically driven reflection light barrier having a light emitting diode, a pulse generator connected electrically to the light emitting diode to produce light pulses and a phototransistor having a collector and an emitter. The phototransistor and the light emitting diode are positioned on the transparent element so the phototransistor receives reflected light produced by the LED. A resistor connects a power supply including a circuit, which can double an operating voltage in the motor vehicle, to the collector of the phototransistor. To neutralize the effects of stray light, e.g.

Abstract: In an electrical equipment such as a control center, operation of space heaters is controlled on the basis of humidity detected by a humidity sensor plus a differential value of an effective value of leakage current flowing through insulating materials in the control center.

Abstract: A raindrop sensor attached to a plate such as a windshield of a car. A first piezoelectric element as an ultrasonic generator is fitted to the plate via a first coupler. The coupler fixes the first element in an inclined state by a predetermined angle relative to the plate. Thereby, elastic waves or ultrasonic waves from the first element are transmitted while being repeatedly reflected in the plate. A second piezoelectric element as an electro-acoustic transducer is fitted to the plate via a second coupler. The second element detects amplitude of the ultrasonic waves transmitted in the plate.

Abstract: A rain gauge having a collecting funnel and a discharged nozzle is provided with a detector for detecting the abstraction of a filter at the input of the nozzle. The detector comprises a light source disposed on an upper portion of said funnel and illuminating the bottom of the funnel above the filter. A sensor located outside of the funnel and nozzle, detects light which is reflected and diffused by the inner surface of the funnel and which passed through the filter and along the nozzle. The sensor is offset laterally with respect to the nozzle. An electronic box is connected to the source for causing the source to emit light pulses at regular time intervals and is connected to the sensor for detecting those output signals of the sensor which exceed a predetermined threshold.

Abstract: A device and method for detecting the nature and condition of ice, water or air on a surface by producing output signals by measurement of dynamic dielectric constant and electrical conductivity of the material on the surface and decoding digital signals therefrom to display information as to the condition. More particularly, a sensing apparatus for producing output voltage signals in response to the formation of ice, water or air at a surface and processing a combination of voltage levels as digital signals to decoding circuitry to provide information which is independent of contamination and impurities and of the size and nature of sensor elements.

Abstract: A method and apparatus are provided for acoustically measuring precipitat rates and total amounts of rainfall. The rainfall is collected in a reservoir and drained through a gravity feed tube system. The gravity feed tube system receives a steady flow of rainfall draining from the reservoir and converts the steady flow into drops by means of surface tension within the tube system. The formed drops exit the tube system and impact a surface that is acoustically responsive to the impact. The acoustically responsive surface is monitored to count the number of drops impacting same, wherein the number of drops counted is indicative of the precipitation rate and total amount of rainfall.

Abstract: A moisture detecting system employs a body of porous concrete with electrodes embedded therein. The body of concrete is contained within a housing having an opening in the top thereof to admit rain. The body may also have electrical probes therein connected to the electrodes, which probes can be embedded in the ground to detect moisture therein.

Abstract: A device for detecting a boiling condition of a liquid including a moisture sensor coupled to a detection circuit that provides an output signal, the output signal being coupled to any of various devices for, among things, providing an alarm signal, controlling a heating element, or turning a heating element off.

Abstract: A device for measurement of moisture in a body of particulate material, such as a grain in a pile or in a silo, is in the form of a spear with a set of conductive plates 2 carried at one end of a shaft 1 for immersion in the body of particulate material, and a read out meter 4 and carrying handle 3 at the other end of the shaft. Normally the set of conductive plates measure capacitance of the material via a phase locked loop oscillatory circuit. The plates are disposed and shaped to facilitate entry into and removal from the body of particulate material.

Abstract: Known and novel 4-aryl-4-piperidinecarbinols and heterocyclic analogs are useful as analgesics. Also provided are novel pyrrolidinecarbinols and hexhydroazepine carbinols which are useful as analgesics, antidepressants and, in some cases, as anorectic agents.

Abstract: The present invention constitutes a rain sampling device adapted for independent operation at locations remote from the user which allows rainfall to be sampled in accordance with any schedule desired by the user. The rain sampling device includes a mechanism for directing wet precipitation into a chamber, a chamber for temporarily holding the precipitation during the process of collection, a valve mechanism for controllably releasing samples of said precipitation from said chamber, a means for distributing the samples released from the holding chamber into vessels adapted for permanently retaining these samples, and an electrical mechanism for regulating the operation of the device.

Abstract: A rain sensor operates such that when a raindrop cuts off a direct light beam from a transmitter to a detector, the output level of the detector is lowered. A convex member is disposed to prevent a portion of the light emitted from the transmitter from reflecting and then reaching the detector. Thus, detecting error due to such reflected light is reduced.

Abstract: A series of substantially horizontally disposed and extended chimes are mounted upon a bracket and positioned to interrupt the fall of rain adjacent a building. The impact of rain or other precipitation upon the chimes gives forth a pleasing sound which is soothing and in many cases soporific for the individuals within the building. The chime means may be of various shapes and arrangements and a transmission apparatus may be provided to conduct the sound of the chimes into the building structure, although the sound of the rain will normally be conducted through an open window or the like into the interior during the sleeping or resting periods of individuals within the building.

Abstract: The device for visibility measurement is designed primarily for use in motor vehicles. A light emitter is arranged inside the driver's compartment preferably on the rear view mirror in front of the windshield. The light emitter generates light pulses or flashes radiating through the windshield. The light scattered back due to soiling on the inside and outside of the windshield or in scatter zones, formed by fog or smoke or the like, in front of the windshield, impinges a light sensor, preferably likewise arranged on the rear view mirror inside the driver's compartment. By utilizing light pulses of various wavelengths and processing of the output signals of the light sensor in predetermined or predeterminable time windows or intervals, not only the respective visibility but also the type of viewing impairment can be determined.

Abstract: A detection and location system, e.g. for liquid leaks, comprising a trunk line sensor cable and a plurality of branch line cables at intermediate points of the trunk cable. Each of the cables comprises two insulated conductors and two non-insulated conductors, e.g. conductive polymer-coated wires, which become connected upon occurrence of a leak. In one embodiment, each of the insulated conductors in the trunk line is continuous and each of the non-insulated conductors is discontinuous at each intermediate point; the branch line conductors are respectively connected to the discontinuous ends of the non-insulated trunk line conductors, and are connected in pairs of one insulated and one non-insulated conductor at the end of each branch.

Abstract: A water conservation system that connects between a standard irrigation system that is controlled by a clock, and the water control valves of that system in order to limit the flow of water during timed irrigation cycles. When the timed watering cycles are initiated by the standard irrigation system, the water conservation device senses the moisture in the soil and compares it with preset wet and dry moisture limits and scales back each of the watering cycles in proportion to the moisture content of the ground to thereby conserve irrigation water that is applied to a ground area. The device includes a moisture sensor, a central processing unit, and a solid state memory that is connected to the central processing unit and the moisture sensor.

Abstract: A hail sensor is disclosed which contains a piezoelectric transducer positioned to produce an output signal when it is vibrated by a hailstone. In one embodiment, the transducer is mounted on a perforated member which is exposed to falling precipitation. In an alternative embodiment, the hailstone impacts a rebound surface and is deflected toward the transducer where an electrical output is produced.

Abstract: A hot-stick mountable, line powered, EHV conductor mounted environmental monitoring apparatus. The sensor module contains sensors for monitoring solar insolation, wind speed, lightning flashes, ambient temperature, relative humidity and dew point, precipitation, conductor icing, acoustic corona detection and conductor vibration. The power line environmental monitoring sensor module is configured to be corona free and can be installed on or removed from an energized high voltage power conductor. Data commensurate with the measured parameters is communicated from the sensor module to a Central or Regional Power Dispatch Center via a Geosynchronous Orbiting Environmental satellite (GOES) or to a ground station in the vicinity of the sensor module.

Abstract: A hygrometer of the electrical impedance type includes a sensing element (1) having a porous moisture adsorbing layer (3), the electrical properties of which vary with the quantity of water vapour adsorbed on it sandwich between a substrate (2) and a porous conducting electrode (4). The conducting electrode (4) is divided into a number of separate measuring zones (6A, 6 and 6C) by gaps (5). The hygrometer also includes a redundancy system circuit (7) which is connected to each of the separate measuring zones (6A, 6B and 6C) and which only provides a moisture indication when the output from at least two of the zones (6A, 6B and 6C) are in agreement. This arrangement enables failures of the sensing element (1) to be detected and distinguished from a false moisture indication.