Abstract: An ambient condition detector includes at least a sensor for a first ambient condition and a second, sensor which is responsive to a second ambient condition not necessarily correlated to the first condition. Control circuitry, coupled to both sensors, processes an output from the first sensor to reduce transients and/or noise therein which are not correlated to the first ambient condition. Processing characteristics are altered in response to an output from the second sensor. The processing can take place at the detector or, in part, at the detector and, in part, at a displaced, common control element. The output from the first sensor can also be used to modify the processing of the output of the second sensor.

Abstract: An incipient failure indication apparatus for an environmental control system which includes a heat exchanger through which air flows and a temperature control thermostat. The indication apparatus includes an indicator having an alarm in communication with a control board, the control board in communication with the thermostat. The alarm has a visual indicator and/or an aural indicator, whereby the attention of a person is attracted to the indicator upon activation of the alarm. A first temperature sensor is disposed on the upstream side of the heat exchanger and a second temperature sensor is disposed on the downstream side of the heat exchanger, whereby the temperature sensors respectively sense the temperature of the air upstream and downstream of the heat exchanger. The first and second temperature sensors are in communication with the control board, and the control board has means for comparing the temperatures sensed thereby.

Abstract: An online early warning detection system of runaway initiation in a batch chemical reactor. The system includes sensors for measuring the temperature in the reactor and/or jacket in different regions and at different instants and a device for deducing therefrom criteria for dangerous runaway conditions.

Abstract: In order to achieve an aspect of the present invention, a rear vehicle detecting apparatus of a vehicle include an alarm unit, a temperature detecting section, a reference temperature data generating section, a comparing section, and a drive section. The temperature detecting section detects a first temperature data based on heat radiated from another vehicle which exists behind the vehicle. The reference temperature data generating section generates a second temperature data as a reference. The comparing section compares the first temperature data and the second temperature data. The driving section drives the alarm unit based on the comparing result by the comparing section.

Abstract: An apparatus for monitoring a thermal state of a system includes a thermal management integrated circuit (IC). The thermal management IC is coupled to receive a remote temperature signal. The remote temperature signal is indicative of a system temperature. The thermal management IC includes a software programmable temperature threshold setpoint, and a hardware programmable temperature critical threshold setpoint.

Abstract: A system is disclosed for determining the temperature of a cooktop having an upper surface and a lower surface. At least one controllable energy source is located below the lower surface of the cooktop to heat the area above the energy source on the cooktop, and at least one sensor with at least one detector to detect infrared radiation from the cooktop above the energy source. The level of infrared radiation is representative of the temperature of the cooktop, which may be glass ceramic. The sensor provides a signal indicative of the temperature of the cooktop which is then used to control the energy source in order to protect the cooktop from extreme temperatures. The signal may be alternatively utilized to provide an indication of a hot cooktop surface after the energy sources have been turned off. The signal optionally is also utilized to provide automatic control of the energy source to maintain a predetermined temperature, or to prevent exceeding a maximum temperature.

Abstract: A process for indicating the likelihood of cook-off for energetic materials by calculating the heat flux and chemical venting relative to known crial parameters for the energetic materials. The process further may include an alarm.

Abstract: A system for indicating by means of at least one warning light the residual heat of at least one pan support grid for a gas burner in domestic cooking or heating appliances controlled by an electronic control device, in which the residual heat of the grid is measured indirectly by the electronic control device on the basis of data relative to the flame level set for the burner and the time for which said flame level is maintained, these data being corrected by a factor which takes account of the physical characteristics of the grid, such that the warning light is and remains activated when the residual heat of the grid exceeds a predetermined safety threshold (A) for its handling by the user.

Abstract: A method and apparatus which reduces flame emissions from an electronics enclosure in the event of a fire within the enclosure. At least one fan is utilized to provide air flow along an air flow path between an air intake port and an air exhaust port of the enclosure. At least one heat sensor, such as a linear heat detector cable, detects an over-temperature condition within air flow path when the temperature in the air flow path exceeds a predetermined threshold temperature. The sensors are coupled to a fan controller. In response to the detection by the controller of the over-temperature condition indicated by one or multiple sensors disposed within the air flow path, the fans are disabled to avoid the fanning of flames within the enclosure and the exhaust of flames from the enclosure.

Abstract: The performance of an HVAC system in a building is monitored by connecting a thermostat to an alarm system which is equipped to provide notification of alarm conditions through telecommunication or other direct means to some responsible entity. The alarm system access to telecommunications is employed to forward indicators of HVAC fault to predetermined offsite locations from where corrective action can be provided. The system includes a presumed fault condition processor which employs data from the thermostat to indicate to the alarm system that notification should take place.

Abstract: A protective device for storage and transport containers comprises, in accordance with the present invention, a housing or frame carrying a sensor for detecting orientation, an attachment element for securing the housing or frame to a container, an alarm mounted to the housing or frame and operatively coupled to the sensor for generating a cognizable alert signal upon detection by the sensor that the container is in an orientation other than a predetermined preferred orientation, and an activation element mounted to the housing or frame and operatively connected to the sensor and/or the alarm for enabling operation of that component after securing of the housing or frame to the container. The activation element preferably includes a switching component for enabling operation of the alarm only after securing of the housing or frame to the container.

Abstract: An electronic freezer thermometer alarm computes an estimation of contents temperature in a freezer from the freezer air temperature. The calculated contents temperature is displayed by a LCD display and is used to trigger a sound alarm, by use of a piezoelectric buzzer, in case of too high a value. Alternatively, the freezer air temperature is used to start a timer that triggers the alarm several minutes after the freezer air temperature have risen above the limit value. In this case, the displayed temperature is the freezer air temperature. In both cases, freezer air temperature acquisition is done by the resistance measurement of a thermoresistor placed into a small case constituting the temperature probe. The thermometer housing has two magnets to keep on freezer external surface. The temperature probe is connected to the housing by a small thickness of wire going under the freezer door gasket. The thermometer is energized by a lithium battery placed into the case.

Abstract: A freeze point protection method and system is provided for water cooled chillers. The method prevents freezing of chilled water and damage to the chiller. The method allows the evaporator temperature to drop below a freezing temperature for a predetermined amount of time prior to shutting down the chiller. The temperature of the refrigerant in the water chiller is periodically sensed. The amount of time that the chiller is below a predetermined freezing temperature is periodically counted and compared with a determined maximum time that the chiller may operate at a sensed temperature below the predetermined freezing temperature without damaging the chiller. The method will shut down the water chiller if the counted time exceeds the determined maximum time. A system for shutting down a water cooled chiller to prevent freezing of chilled water is also provided.

Abstract: Whether a thermal image is in a steady state or an unsteady state is judged based on measurement values of temperatures of objects and ambient temperature and previously obtained relational expressions between ambient temperature and the temperatures of the objects and an air conditioner is controlled based on the result of the judgment.

Abstract: An ambient condition detector includes a sensor for a first ambient condition and a second, sensor which is responsive to a second ambient condition not necessarily correlated to the first condition. Control circuitry, coupled to both sensors, processes an output from the first sensor to reduce transients and/or noise therein which are not correlated to the first ambient condition. Processing characteristics are altered in response to an output from the second sensor. The processing can take place at the detector or, in part, at the detector and, in part, at a displaced, common control element.

Abstract: The present invention, in one form, is an alarm system for detecting the presence of a child locked within a parked automobile during extreme temperatures. The alarm system includes a temperature detecting element and a child detecting element electrically coupled to an AND gate. The temperature detecting element transmits an extreme temperature signal to the AND gate if the temperature within the automobile exceeds a pre-selected maximum temperature. The child detecting element transmits a child detection signal to the AND gate when it detects a child within the automobile. The AND gate, upon receiving both the child detection signal and the extreme temperature signal, transmits and alarm signal.

Abstract: A fire alarm radio transmitter and receiver set is provided with a radio transmitter and a radio receiver. The radio transmitter has a plurality of temperature sensors, a first memory keeping data including an address of a building, a first controller for generating transmission data by combining the data and an identification code and for allowing an alarm to emit an alarm signal, a frequency generator for generating a frequency radio signal and for mixing the frequency radio signal with the transmission data and a transmitter for transmitting the transmission data.

Abstract: A brake lining wear indicator utilizes a temperature sensor assembly embedded in a brake lining of a drum brake assembly. The temperature sensor assembly includes two temperature sensors with a first temperature sensor located at a first distance X from the wear surface of the brake lining and a second temperature sensor located at a second distance X+d from the wear surface. A timing device measures the time period for the first temperature sensor to reach a first predetermined temperature and measures the time period for the second temperature sensor to reach a second predetermined temperature. The remaining useful thickness of the brake lining is determined based on the ratio of the respective time periods. Thus, the indicator provides a time-temperature based determination of when the brake linings should be replaced.

Abstract: A brake lining wear indicator utilizes a temperature sensor assembly embedded in a brake lining of a drum brake assembly. The temperature sensor assembly includes two temperature sensors with a first temperature sensor located at a first distance X from the wear surface of the brake lining and a second temperature sensor located at a second distance X+d from the wear surface. A timing device measures the time period for the first temperature sensor to reach a first predetermined temperature and measures the time period for the second temperature sensor to reach a second predetermined temperature. The remaining useful thickness of the brake lining is determined based on the ratio of the respective time periods. Thus, the indicator provides a time-temperature based determination of when the brake linings should be replaced.

Abstract: The present invention relates to an electric appliance and a remaining life estimation system wherein the electric appliance having a printed circuit board on which at least LSI components are mounted includes an IC with sensor. The IC includes a time monitor for calculating the operation status which is a use condition affecting the life of a reusable component of the appliance, a temperature and humidity sensor for detecting at least temperature and humidity environmental conditions affecting the life of the reusable component, and a memory for storing the history of temperature and humidity in correspondence with the history of operation status.

Abstract: There is provided an alarm system for detecting and warning of the presence of alarm and trouble conditions in a plurality of zones. The system comprises a control panel having a central processing unit and a plurality of alarm devices, each having a microprocessor, that are electrically coupled to the control panel. In particular, the present invention is a two-tier monitoring system such that each alarm device monitors its zone for a shorter rolling time period and the control panel monitors the same zone of the alarm device for a longer rolling time period. An electronic circuit of the alarm device, including the microprocessor, reads and processes data received from various sensors of the alarm device. Periodically, the alarm device updates a first reference value stored in its memory based on the data received from the sensors during the shorter rolling time period.

Abstract: An over temperature protection method and its circuital device for a central processing unit includes a read and write memory unit having pre-stored therein; an instruction for identifying a type of CPU and automatically predetermining the maximum allowable over temperature for the CPU. An over temperature is detected by a heat sensitive resistance installed at the space immediately under the CPU to cause an audio frequency alarm circuit to output a sound alarm and also cause the CPU to slow down its operation speed to an appropriate reduced rate to prevent CPU from being damaged by over heat or other loss caused by interrupting CPU operation. After recovery of temperature to a normal value, the CPU can be instructed to operate with its normal speed.

Abstract: A system and a method for dynamically adjusting a level of filtering or smoothing applied to data received from fire detectors produces shortened response times for detection of a fire condition while at the same time minimizing the effects of uncorrelated noise in the absence of any fire condition. An increasing probability of a fire results in less filtering. Increasing values of the input signal from a respective detector, indicative of an increasing selected ambient condition such as combustion or temperature, provide a control input for reducing or bypassing the level of filtering of the respective input signal thereby reducing system response time. Where the unfiltered input data from a respective detector indicates a combustion or temperature profile moving toward clear air, the filtering or smoothing level can also be dynamically decreased thereby enabling the filtered signal values to return to their respective clear air values faster than would otherwise be the case.

Abstract: Wall temperatures of a reactor vessel are monitored by arranging an optical fibre in thermal contact with the wall and employing an optical time domain reflectometry system to monitor the respective temperatures at different points along the fibre. Such a monitoring method can be cheaper and more reliable than comparable prior art methods. An alarm may be triggered automatically when hot spots are detected.

Abstract: A stove including circuitry to facilitate avoidance of fires such as may be caused by grease or another flammable substance present on the stove burner. The circuitry detects when such burner has been set above a predetermined temperature or power level for a selected duration and responsively disengages same. In presently preferred embodiments, the circuitry includes an indicator circuit operative to produce an output when the predetermined temperature or power level has been exceeded. This output initiates operation of a timer circuit which will itself produce an output after the selected duration. An appropriate switching circuit is provided to then disengage the burner as desired.

Abstract: The system of the subject invention includes an antenna system, a surface apparatus and a battery-powered remote apparatus useful for applications such as well bore telemetry. In well bore telemetry, the surface apparatus is located uphole on the earth's surface and the remote apparatus is positioned at a remote location downhole in a well bore. The remote apparatus includes a sensor/transmitter unit for sensing physical characteristics such as pressure and/or temperature. The remote apparatus conserves power stored in its battery by transmitting change-in-pressure and/or change-in-temperature data that requires less power for transmission than absolute pressure and/or temperature data. The remote apparatus also conserves power by transmitting absolute pressure data in a single data frame and transmitting absolute temperature data in portions in a series of data frames.

Abstract: A vacuum controlling apparatus is provided. The vacuum level of a vacuum chamber can be accurately maintained by measuring and controlling the vacuum level of the vacuum chamber by using six parameters: desired pressure, predetermined time for reaching the desired pressure, predetermined temperature, actual pressure, actual time for reaching the desired pressure, and actual temperature.

Abstract: A safety device for irons used for models includes a control electrical circuit board accommodated within an iron and mounted with a temperature setting knob controllable by a variable resistor, a central processing unit, an output control device, a heater, a sensor, and an indicator having three light emitting diodes of three different colors. When power is on, the central processing unit will examine the control circuit to ensure that the iron is in a normal state before causing the iron to be heated to a set temperature. The central processing unit will keep on checking the control circuit and, once the temperature of the iron is sensed to be unstable or abnormal, the light emitting diodes will indicate trouble and power will be cut off to protect the control circuit board.

Abstract: A method for displaying the outside temperature within a motor vehicle in which measured values of the outside temperature are displayed with a greater time delay in the case of increasing temperature on an outside-temperature sensor than in the case of a decreasing temperature. In order to suppress erroneous display of the outside temperature, the time delay is varied as a function of the temperature of the engine.

Abstract: A portable fire alarm system setting device allows easy confirmation of information such as address information set in a storage element which cannot be seen visually from the outside of a terminal device, for example, a fire detector, and also allows the set information to be changed when necessary. The setting device for the fire alarm system comprises bases 33 and 34 for transmitting power and information signals regarding, for example, an address to the fire detector, the bases having removably connected thereto fire detectors 20 and 21 for the fire alarm system; a microcomputer 5 having a confirmation mode and a setting mode for controlling the sending and receiving of, for example, address information signals to and from the fire detector through transmission circuits 10 and 11; an indicator section 8 connected to the microcomputer 5 for indicating the fire detector address; and an operation section 7 used to send out an address as operation information to the fire detector.

Abstract: An electronic refrigeration and air conditioner monitor and alarm system monitors air conditioning and refrigeration systems for inefficiencies that waste energy. The device monitors and analyzes the temperatures of the suction line of such systems for variances that indicate malfunctions or abnormal operation of the system. The device provides both an audible and visual alert to warn the end user that the equipment is in need of maintenance and/or repair.

Abstract: An early stage fire detecting apparatus is arranged such that a fire state is discriminated based on a fire probability output from a signal processing network. The fire probability being prepared in such a manner that outputs from a high sensitivity smoke sensor SS and a smell sensor NS, from which responses can be obtained at the early stage of a fire, are subjected to signal processing. Fire information composed of a value at a given moment of smoke and a difference indicating the increase or decrease of the value at a given moment of the smoke and a value at a given moment of smell and a difference indicating the increase or decrease of the value at a given moment of the smell are input to the signal processing network. The signal processing network outputs the above fire probability based on a table (RAM12) defining a fire probability to be obtained from the above fire information and weighting values (RAM13).

Abstract: In a fire alarm device for detecting the physical quantities of substances arising from the outbreak of a fire and giving a fire alarm, membership functions showing the correlation between an arising quantities calculated by the detected physical quantities and the danger degree which a man would feel with respect to the physical quantities are preset, the danger degree with respect to the arising value calculated by the physical quantities actually detected by a detection means is obtained by using the membership functions, and an alarm and control in accordance with the danger degree is given. Therefore, there is provided a fire alarm device capable of judging the outbreak of a fire based on an actual fire situation and giving an alarm and control in accordance with the degree of danger which a man would feel with respect to the scale, situation and so on of the fire.

Abstract: An apparatus which determines a kind of an object to warn a driver based on the kind of the object and properly performs deceleration and braking operations based on a position of the object and a speed of the vehicle is disclosed. An infrared-ray camera is employed to detect a shape and a temperature of the object. A digital signal processing technique is utilized for displaying the temperature distribution of the object. Therefore, using the apparatus, it is able to distinguish the shape and the kind of the object in the night time and the vehicle is suitably decelerated and/or stopped based on conditions.

Abstract: A surveillance and alarm device for room spaces, comprising an infrared radar for controlling the lights as well as a fire and burglar alarm. A basic alarm is provided with a light controller to be connected in series with a ceiling light fixture in a room under surveillance, and is further provided with a microprocessor or some other intelligent control circuit, adapted to control the alarm actions of said device either on the basis of a command issued by a lamp light switch or a wireless remote controller or on the basis of a command issued by a key switch. The light controller included in the basic alarm switches on said lighting fixture as someone enters a room under surveillance or flashes said lighting fixture in connection with an alarm.

Abstract: A fire detector is capable of self-detecting its own malfunction and is also capable of quickly announcing a failure of high-level emergency in the fire detector. A plurality of determining values are established for the output level of a physical quantity detector for detecting the physical quantity of a fire phenomenon such as smoke, and a different time is set for each of the determining values. A shorter time is set for greater deviation from the normal value of the output level. It is determined that the physical quantity detector is faulty if it is detected that the output level of the physical quantity detector continuously exceeds any of the established determining values for not less than the time which has been set for that particular determining value.

Abstract: A fire disaster monitoring system of the present invention has a control unit and a fire sensor. The fire sensor includes a sensor base and a sensor body. The sensor base incorporates a first memory which stores first address information of the first memory. The sensor body incorporates a second memory and a CPU therein. The second memory stores second address information of the sensor body. The CPU includes an address reader, a comparator and an address generator. When the power is turned on, the address reader reads the address information in the first memory, and reads the address information in the second memory. The comparator compares the read pieces of address information with each other. When the comparison result by the comparator indicates agreement, the address generator leaves the address information in the second memory as valid data.

Abstract: An automatic temperature alarm system is disclosed for alerting an operator of a heated apparatus that the apparatus has been heated and untouched for an excessive period of time. In a particular embodiment, the invention comprises a temperature sensor affixed to the heated apparatus that senses its temperature; a vibration sensor that senses motion of the apparatus; a horn to alert the operator; and a system control intelligence in communication with the temperature and vibration sensors and horn for setting an alarm timer to measure an alarm period in response to sensed temperatures and motions and for activating the horn upon expiration of the alarm period.

Abstract: A fire alarm system exhibiting satisfactory reliability and capable of easily and assuredly setting address and various discrimination values to terminal units. The fire alarm system has a setting unit including a first command unit, a first discrimination unit for discriminating whether or not a transmitted set value transmitted by the first command unit and a set value received from a detector coincide with each other, a second command unit for transmitting the set value to the detector when the received set value and the transmitted set value coincide with each other, and a second discrimination unit for discriminating whether or not the received set value and the set value transmitted from the first or the second command unit coincide with each other.

Abstract: A fire alarm system automatically adjusts sensitivity of individual sensors based on evaluation of background level over a period of time. High sensor signals which do not trigger a fire alarm may, after a delay time, result in decreased sensitivity to avoid false alarms. On the other hand, low peak values stored over a period on the order of months result in an automatic increase in sensitivity of the system. The sensitivity is adjusted by changing the delta threshold of an alarm threshold over a quiescent sensor signal average.

Abstract: A heat detector uses a single comparator operating in conjunction with a dynamically changing thermal reference that ensures quick response to rapid rates of thermal change and a fixed threshold that indicates an ambient temperature exceeds a threshold temperature. The inputs of the comparator receive different ones of the output signals of two thermal sensors. One thermal sensor responds nearly instantaneously to changes in ambient thermal conditions. The other thermal sensor is mounted on a printed circuit board operating as a heat sink and responds more slowly to changes in ambient thermal conditions. The difference between the thermal sensor output signals is zero at a lower ambient temperature when the rate of thermal change exceeds a preset amount and at a higher ambient temperature when the rate of thermal change is relatively slow.

Abstract: A fire alarm system has address numbers that are given to terminal devices, such as transmitters, analog fire detectors and addressable fire detectors, and are given to the fire receiver similarly to the foregoing terminal devices. A signal to be transmitted from the fire receiver is given the address of the fire receiver as the sender address as well as the addresses of the terminal devices which are the information receivers, and a signal to be transmitted from the terminal device is given the address of the receiver of the signal as well as the self-address. As a result, information can be directly transmitted to the terminal devices, and therefore, the load of the fire receiver can be reduced. When the fire receiver and the terminal device transmit the data signal, a data length signal denoting the length of the data to be transmitted is calculated, and the data length signal is transmitted together with the data signal.

Abstract: A container for transporting, storing, and handling sensitive items has a housing within which at least one sensitive item is stowable, and a monitoring system for monitoring a plurality of separate parameters to which the sensitive item(s) are sensitive. The monitoring system records and provides data regarding the parameters to which the sensitive item(s) are sensitive. The monitoring systems preferably utilizes such sensors as a vibration sensor, a shock sensor, a temperature sensor, a humidity sensor, a magnetic field sensor, an unauthorized opening sensor, and/or an attitude sensor.

Abstract: An exhaust gas temperature indicator for a gas turbine engine is disclosed in which data representing discrete overtemperature events occurring at different times is stored in a nonvolatile memory for later retrieval and display on an event-by-event basis. A character display is used to provide detailed digital, alphanumeric or other character information relating to each overtemperature event, such as the number, temperature zone, peak temperature and duration of the event. An indicator is provided for indicating the presence of unacknowledged temperature data in the memory device, and a maximum exhaust gas temperature value for an aircraft flight is stored. An analog display for continuously displaying current exhaust gas temperature values is provided in conjunction with a character display for displaying either current or stored values.

Abstract: A display is provided for indicating changes between first and second operating conditions in an appliance such as a clothes dryer. A sensing circuit senses changes in operating conditions within the appliance. A heater is connected to the sensing circuit and is responsive to various signals produced by the sensing circuit to generate heat. An elongated thermally conductive substrate is mounted adjacent to the heater for receiving and conducting thermal energy produced by the heater. A layer of thermochromic material overlies the substrate and is capable of changing colors in response to changes in the temperature of the conductive substrate.

Abstract: In a fire-alarm system in which a plurality of terminal units are connected to a fire receiver via a main signal line, the fire receiver polls each terminal unit, and the terminal unit called by the polling sends a current signal back to the fire receiver. A voltage signal receiving circuit having a DC signal component blocker is provided in each terminal unit for removing a DC signal component of a polling signal so as to detect only an AC signal component of the polling signal, and a current signal transmitting circuit having a constant-current circuit is provided so that the constant-current circuit is turned on/off to deliver the return signal. Therefore, a threshold used for signal discrimination in the voltage signal receiving circuit can be easily set. The current consumed by the terminal unit becomes constant regardless of the number of the terminal units connected when it is outputting the current signal, resulting in the terminal unit not wastefully consuming an extra current.

Abstract: A radio analog sensor for transmitting analog signals of a temperature or smoke density to a remote place by radio is used as each of sub devices 12-1 to 12-n. When a change of the analog detection signals of a temperature, a smoke density or the like, which is detected by the analog sensor 10 connected to each of the sub devices, is greater than a predetermined value, the analog signals which have been so far stored in a memory are collectively transmitted to the receiver side by radio. Periodic information is also sent from each of the sub devices 12-1 to 12-n once every two hours so as to supervise the state of the sensors. This permits reliable transmission of necessary data to a remote place without decreasing the life of the battery.

Abstract: A microprocessor based temperature determination system for displaying outside ambient temperature inside of an automotive vehicle. The system utilizes sensors for vehicle speed, engine temperature and exterior temperature measurements in order to accurately determine a true temperature indication, taking into account non-ambient heat sources. The temperature displayed to the vehicle's occupants is either the current reading from the exterior temperature sensor, or is an averaged temperature value. The averaged temperature value is determined by averaging the value of the temperature sensor's readings over a ten second interval, taking a sample every one half second.

Abstract: An electronic clinical thermometer which detects temperature of a measured part and determines equilibrium temperature by prediction calculation based on change of the detected temperature. One of classified temperature rise data groups is selected based on the change of the detected temperature and one of prediction equations and a set of prediction parameters are designated in accordance with the selected data group. The selected data group can be changed based on change of the detected temperature in a predetermined period after the selection of data group. Further, reliability of the measurement is judged based on the detected or predicted temperature and the predicted value can be corrected if the reliability is insufficient.

Abstract: The present invention utilizes a single temperature sensor and heating element in thermal contact with the sensing surface. The signal from the temperature sensor and the signal from the heating element are input to a standard microprocessor integrated circuit. The microprocessor continuously compares the two signals to accurately assess whether snow is present on the sensing surface. The present invention eliminates the requirement for a moving airmass to accurately assess the presence of snow on the sensing surface. The present invention does not ingest snow nor require ice formation to operate. The snow sensing surface and the sensor housing are weather and debris resistant. The present invention may be mounted in an elevated position or in any suitable location proximate an area to be monitored. The present invention serves as an integral part of a closed loop control system for numerous snow removal applications.