Abstract: Methods and systems for diagnosing a sensor can involve detecting a group of sensor signals output from a sensor, and differentiating from among the sensor signals to distinguish inequalities in the sensor signals for an indication of a potential fault in the sensor. A small sensor signal can be identified from a larger sensor signal among the sensor signals for the indication of the potential fault in the sensor. The sensor can include a group of piezo-resistive Wheatstone bridge elements, and in some embodiments, the sensor may be a pressure transmitter.

Abstract: A high temperature dry block temperature calibrator relates to the technical field of temperature calibration. The high temperature dry block temperature calibrator includes a high temperature furnace, a control board module, a system board module, a measuring board module, a lower support, and a housing. The high temperature furnace and the control board module are mounted on the lower support. The system board module and the measuring board module are mounted on the front side surface of the housing. The housing is clipped to the periphery of the lower support and the high temperature furnace and the control board module are accommodated in the housing. The modules are independent of each other and can be removed separately, thereby facilitating maintenance and replacement. The high temperature dry block temperature calibrator can be used for calibrating the temperature of a high temperature element to be measured.

Abstract: A device for measuring at least one physical quantity includes a direct voltage source and a measuring sensor coupled to the voltage source, which sensor is configured to measure a physical quantity. A current regulator is connected between the direct voltage source and the measuring sensor, and a voltmeter is connected in parallel with the measuring sensor so that a voltage detected by the voltmeter is indicative of the measured quantity.

Abstract: The present invention is aimed to reduce power consumption of a measuring apparatus. A measuring apparatus according to the present invention is to be disposed in an excavation section of an underground excavator. The measuring apparatus according to the present invention includes a first measurement module, a second measurement module, and an information processor. The first measurement module includes a triaxial first accelerometer and a triaxial first magnetometer for performing highly-accurate measurement. The second measurement module includes a triaxial second accelerometer and a triaxial second magnetometer for performing measurement during excavation. The information processor controls the first measurement module and the second measurement module and obtains a position and an attitude of the excavation section based on output data of the first measurement module or the second measurement module. Further, the second accelerometer and the second magnetometer are MEMS sensors.

Abstract: A heat flow sensor configured to provide an indication of temperature relative to a process fluid is provided. The sensor comprises a first resistance temperature detector (RTD) element and a second RTD element spaced within a sheath from the first RTD element. The sensor also includes a set of leads comprising a first subset and a second subset, wherein the first subset is coupled to the first RTD element and the second subset is coupled to the second RTD element.

Abstract: To provide an overheat protection circuit which is not affected by a leak current while being low in current consumption and good in detection accuracy, and a voltage regulator equipped with the overheat protection circuit. An overheat protection circuit is configured to include a leak current detection circuit which detects that a leak current has flowed at a high temperature, a bias circuit which allows a bias current to flow in response to an output signal of the leak current detection circuit, and a temperature detection circuit operated by the bias current.

Abstract: A method and apparatus are provided for indicating the status of the refrigerant charge in an air conditioning system based upon the degree of subcooling present in the condensed refrigerant system temperature measurements. The status of the refrigerant charge in the system is indicated in real-time on a service panel for access by a field service technician. The status of the refrigerant charge in the system on a time-average basis for a specified period of operation is presented on an indicator panel. The indicator panel includes a first indicator light indicating that the refrigerant charge is low, a second indicator light indicating that the refrigerant charge is high, and a third indicator light indicating that the refrigerant charge is correct.

Abstract: A battery pack with a drain plug and a circuit to detect when a liquid coolant has entered the battery pack. The drain plug includes a carrier defining a cavity internal to the carrier, an inlet disposed on a first surface of the carrier and an outlet disposed on a second surface of the carrier where the first surface and the second surface fluidly displaced from one another and coupled to the cavity. A soluble plug may be disposed within the cavity of the carrier; the soluble plug is configured to at least partially dissolve when fluidly coupled with a coolant allowing a portion of the coolant to flow between the inlet and the outlet and out of the battery pack. A strain gauge cooperative with the carrier such that a measured resistance change in the strain gauge corresponds to the soluble plug in contact with the liquid coolant. An associated circuit with the drain plug provides notification of the activation of the drain plug to the on-board computer systems.

Abstract: A temperature detection device includes a diode and an analog-digital converter. An output voltage signal of the diode is applicable to an input of the analog-digital converter. The temperature detection device is adapted for the purpose of coupling a reference voltage of the analog-digital converter and the diode current of the diode such that effects of variations of the reference voltage or the diode current on the digital output signal of the analog-digital converter are partially or completely suppressed.

Abstract: Described is a method and apparatus for compensating for a change in an output characteristic of a temperature sensor due to varying temperature. The temperature sensor includes a temperature sensing core, an analog-to-digital converter, a counter, and a temperature compensating circuit. The temperature sensing core generates a sense voltage corresponding to a sensed temperature. The analog-to-digital converter converts the sense voltage into a digital signal and generates a conversion signal. The temperature compensating circuit generates a counter clock signal that varies according to a temperature change. The counter counts the number of pulses of the counter clock signal according to the conversion signal.

Abstract: An inverter device is provided that can measure a decrease in cooling capacity caused by a finite service life of a cooling fan or clogging of a cooling fin, without being affected by an ambient temperature or a load state. A thermal time constant is calculated in a thermal time constant calculation circuit from a temperature detection value from a temperature detection circuit and a time signal from a timer on the basis of an operation/stop command for the inverter device. The calculated value of the thermal time constant calculated in the thermal time constant calculation circuit is compared by a comparator with a reference value of the thermal time constant that is stored in advance in a memory. Whether the cooling capacity has decreased is determined based on the comparison results.

Abstract: A temperature sensor performs more precise temperature measurement, even when manufacturing fluctuations are present in semiconductor elements forming a circuit for generating a temperature-dependent current.

Abstract: To provide a PDM output temperature sensor, which is reduced in area and consumption power, provided is a PDM output temperature sensor which includes no reference voltage circuit, thereby having a smaller area and consuming less power correspondingly.

Abstract: Temperature detection circuitry is selectively coupled to a thermistor and one of two sources representing the impedance at respective ends of the expected range of temperature to which the thermistor is to be exposed. The offset of an amplifier and a scale factor to account for gain set of the amplifier are determined in an automatic calibration process while coupled to the source(s), and thereafter temperature readings are taken from the thermistor. During the calibration process, if the gain or scale factor are outside of expected ranges, a failure is determined and an alarm given and/or a heater is disabled.

Abstract: The radiometric thermometer includes a microwave sensor and electronic means for processing the electrical signal delivered by the sensor. The electronic means includes means for preamplifying the electrical signal delivered by the microwave sensor; variable-gain amplification means with automatic gain control, which means amplify the signal delivered by the preamplification means, the amplification means having an automatic gain control signal that allows the gain to be automatically adjusted on the basis of the signal output by the amplification means, and electronic temperature measurement means for measuring temperature on the basis of the automatic gain control signal.

Abstract: A method for precision thermal measurement and control, especially for bioreactors, as well as the correction of temperature sensitive probes such as pH and dissolved oxygen. Typical control requirements are +/?0.1° C. The thermal measurement circuit converts a sensor output to a high level voltage or current with great accuracy and provides noise immunity and sensor isolation. While digital outputs from sensor converters can have the greatest noise immunity, the noise associated with digital circuitry may contaminate low level sensor signals so in many cases an analog sensor converter is preferred because of low noise generation, especially if the converter is near the sensor. The circuit is low cost, reliable, generates minimal heat is immune to, and does not generate noise, and requires minimal calibration effort.

Abstract: A method and apparatus for determining an operating voltage lower bound for preventing photovoltaic (PV) cell reverse breakdown during power conversion. The method comprises determining a PV cell operating temperature; computing, at a controller, an operating voltage corresponding to a maximum power point (MPP) based on the PV cell operating temperature; and determining, at the controller, an operating voltage lower bound based on the operating voltage.

Abstract: Provided is a semiconductor temperature sensor having satisfactory linearity of an output voltage with respect to temperature. In a semiconductor temperature sensor (1), even if the temperature increases and a leakage current is generated at bases of a PNP (8) and a PNP (9), a current which flows into emitters of a PNP (7) and the PNP (8) is not affected by the leakage current by virtue of a leakage current compensation current of a PNP (14), and thus, the linearity of the output voltage with respect to the temperature is improved and the accuracy of the semiconductor temperature sensor (1) with respect to the temperature is improved.

Abstract: Two vertically offset thermistors for sensing a fluid such as oil and refrigerant in a compressor shell are monitored by a method that takes into account rapidly changing conditions within the shell. The system can determine the fluid's sump temperature, high/low liquid levels, and can determine whether the thermistors are sensing the fluid as a liquid, gas, or a mixture of the two, such as a foam or mist of liquid and gas. For greater accuracy, thermistor readings can be dithered and filtered to provide temperature or voltage values having more significant digits than the readings originally processed through a limited-bit A/D converter. For faster response, limited microprocessor time is conserved by sampling thermistor readings at strategic periods that enable the microprocessor to identify certain conditions and temperatures via simple delta-temperature ratios and undemanding equations rather than resorting to exponential functions or lookup tables to determine time constants.

Abstract: An exemplary temperature measurement device includes a reference voltage source, a three-wire thermal resistor, a voltage drop amplifier, an operational amplifier and compensation resistors. By using connecting wires with resistance values of the compensation resistors, a relation between an output signal and a resistance of the thermal resistor gives rise to a monotonous function, which is independent of the resistances of the connecting wires. After A/D conversation of an output signal, the resistance of the thermal resistor and a temperature can be calculated based on known functions. Therefore, within an entire measurement range and any length of cable, an influence of the wire resistances can be compensated without switches or jumpers.

Abstract: To provide a PDM output temperature sensor, which is reduced in area and consumption power, provided is a PDM output temperature sensor which includes no reference voltage circuit, thereby having a smaller area and consuming less power correspondingly.

Abstract: In one embodiment, an integrated circuit (IC) is provided with a thermal diode and a constant current source. In this embodiment, the saturation current of the diode may be determined by means external to the IC. During normal operation of the IC, the constant current source drives a current to the diode, and the forward bias voltage of the diode is used as a temperature indicator. In another embodiment, an IC is provided with a pair of thermal diodes and a constant current source. During normal operation of the IC, each of the diodes receives a current of different magnitude from the constant current source, and a comparison of the diodes' forward bias voltages is used as a temperature indicator.

Abstract: Provided is a semiconductor temperature sensor having satisfactory linearity of an output voltage with respect to temperature. In a semiconductor temperature sensor (1), even if the temperature increases and a leakage current is generated at bases of a PNP (8) and a PNP (9), a current which flows into emitters of a PNP (7) and the PNP (8) is not affected by the leakage current by virtue of a leakage current compensation current of a PNP (14), and thus, the linearity of the output voltage with respect to the temperature is improved and the accuracy of the semiconductor temperature sensor (1) with respect to the temperature is improved.

Abstract: A method for digitally controlling the resistive output of a temperature probe is disclosed. The system is comprised of a temperature sensor, a processor and a means under the control of the processor for modifying the resistive output such as a digital potentiometer. In one embodiment, the processor reads the temperature sensor and adjusts the potentiometer based on a correlative or predictive technique so as to provide a modified output that matches that of a standard resistive temperature probe and is compatible for display on a multiparameter monitor.

Abstract: A component arrangement is disclosed herein comprising a temperature sensor integrated in a semiconductor body, said temperature sensor being designed to generate a first temperature signal dependent on a temperature in the semiconductor body; a control device comprising a control amplifier, which has a first and a second input and an output, and comprising a low-pass filter having an input and an output, the input of the low-pass filter being coupled to the output of the control amplifier, the first input of the control amplifier being coupled to the temperature sensor and the second input of the control amplifier being coupled to the output of the low-pass filter; and an output, which is coupled to the output of the control amplifier and at which a second temperature signal is available. A method for determining the temperature in a semiconductor component is also disclosed herein.

Abstract: A method for linearizing a nonlinear curve with a linearization circuit (1), wherein the curve represents the relationship between input signals and output signals of a sensor. An output signal (100, 110, 120) of the sensor, which is respectively associated with an input signal, is displayed with respect to a simple and cost favorable linearization such that the adjustment of the linearization circuit (1) essentially occurs in an automated way utilizing sequence controller (2). A corresponding circuit is also described for practicing the method.

Abstract: A temperature-based cooling device controller is implemented in an integrated circuit such as a microprocessor. The temperature-based cooling device controller includes a register to store a threshold temperature value, a thermal sensor, and clock adjustment logic to activate a cooling device in response to the thermal sensor indicating that the threshold temperature value has been exceeded. In a microprocessor implementation, the microprocessor contains a plurality of thermal sensors each placed in one of a plurality of different locations across the integrated circuit and an averaging mechanism to calculate an average temperature from the plurality of thermal sensors. Threshold adjustment logic increases the threshold temperature value to a new threshold temperature value in response to the thermal sensor indicating that the threshold temperature value has been exceeded. Threshold adjustment logic further lowers the new threshold temperature to detect decreases in temperature.

Abstract: An apparatus and method for measuring the temperature in an oven includes a circuit and software algorithm that reads the voltage across a standard resistive temperature device (RTD) or thermistor to determine temperature measured by the device. Using an unregulated high voltage supply to increase the gain and resolution, it overcomes the problems of small changes in resistance with respect to temperature. An additional input to measure the unregulated supply voltage is used as a reference voltage input. The apparatus includes resistor dividers for both the temperature sensor and reference voltages, a microprocessor having analog inputs, and additional components for noise suppression and open sensor protection.

Abstract: A patient temperature repeating system and a method of repeating patient temperature information from a resistive-type patient temperature sensor allow one or more medical instruments to utilize a single patient temperature sensor. In one embodiment, the patient temperature repeating system (10) includes input and output connectors (12, 14), a microprocessor (20), optical isolators (22), a coarse digital potentiometer (24) in parallel with a fine digital potentiometer (26), a current sense resistor (28), amplifiers (30A, 30B), analog-to-digital converters (32A, 32B), a filter (34), fuses (36), a non-volatile memory device (38), and a relay (40).

Abstract: A temperature-based cooling device controller includes a register to store a threshold temperature value, a thermal sensor, and cooling activation logic to activate an active cooling device in response to an interrupt signal. The thermal sensor includes a current source, a voltage reference coupled to the current source to provide a bandgap reference voltage, wherein the bandgap reference voltage is substantially constant over a range of temperatures, programmable circuitry providing an output voltage that varies with the integrated circuit temperature and in accordance with the register value, and a comparator, wherein the comparator generates an interrupt signal if a difference between the output voltage and the bandgap reference voltage indicates that the threshold temperature has been exceeded.

Abstract: A temperature measurement device includes at least one constant current generator to provide a first current and a second current to a temperature sensor, and a signal processing element to provide an analog output signal corresponding to a temperature of the temperature sensor based on a difference between a first voltage of the temperature sensor at the first current and a second voltage of the temperature sensor at the second current.

Abstract: In a three-wire RTD interface, a known current is connected to a first lead during a first measurement interval. In this configuration, current is directed to the first lead and into an RTD. This results in a first signal indicative of a first voltage drop resulting from the voltage drops across the RTD and the lead resistance of the first lead. During a second measurement interval, current is directed through a second lead having a lead resistance substantially identical to the lead resistance of the first lead. This results in a second signal indicative of the voltage drop resulting from the second lead. The first signal, the second signal, and the known current are then combined to eliminate the effect of the lead resistance and to determine the resistance of the RTD.

Abstract: A temperature determining apparatus produces a predetermined reference voltage from an operating voltage supplied thereto from the outside, divides the reference voltage with a pair of resistance values having different temperature-resistance characteristics to produce a first divided voltage and divides the reference voltage with a pair of resistance values having the same temperature-resistance characteristic to produce a second divided voltage, and compares the first and second divided voltages to determine a threshold temperature. Since the reference voltage is constant as long as an ambient temperature is not changed even when the operating voltage is changed, the first and second divided voltages are not changed depending on the operating voltage, thereby allowing the determination of an ambient temperature with favorable accuracy in a wide range of operating voltages.

Abstract: An integrated circuit includes: a comparator coupled in a configuration to compare two voltages. One of the two voltages includes a semiconductor junction voltage drop. The other of the two voltages includes a voltage signal, X V.sub.t, where V.sub.t is a thermal voltage and X includes a selected signal value, which modulates the thermal voltage. The configuration includes a feedback path to vary X until X V.sub.t approximately equals the voltage including the semiconductor junction voltage drop.

Abstract: A programmable thermal sensor is implemented in an integrated circuit such as a microprocessor. The programmable thermal sensor monitors the temperature of the integrated circuit, and generates an output to indicate that the temperature of the integrated circuit has attained a pre-programmed threshold temperature. In a microprocessor implementation, the microprocessor contains a processor unit, an internal register, microprogram and clock circuitry. The microprogram writes programmable input values, corresponding to threshold temperatures, to the internal register. The programmable thermal sensor reads the programmable input values, and generates an interrupt when the temperature of the microprocessor reaches the threshold temperature. In addition to a programmable thermal sensor, the microprocessor contains a fail safe thermal sensor that halts operation of the microprocessor when the temperature attains a critical temperature.

Abstract: A Linear Integrated Sensing Transmitter Sensor for measuring and reporting temperature has a housing defining a cavity therethrough, a resistance temperature within the housing, and a transmitter disposed within the housing connected to the resistance temperature detector for providing a current which is a linear function of the temperature sensed by the resistance temperature detector. The transmitter further includes an excitation current means for applying an excitation current to the resistance temperature detector, a converter means for converting a detected voltage to a current, and a feedback means for adjusting a feedback current to maintain the voltage as a linear function of the temperature sensed.

Abstract: An error-compensated temperature measurement system has a temperature sensor, an amplifying circuit and a compensation circuit for compensating non-linearities in the amplifying circuit of the temperature sensor. Specifically, the amplifying circuit has an analogue to digital converter exhibiting non-linearity characteristics, and the compensating circuit automatically compensates these non-linearities as well as correcting for the self-zero and self gain characteristics of the amplifying circuit.

Abstract: A temperature detector resistor and a sensor resistor are disposed in an intake manifold of an internal combustion engine. The two resistors each belong to a respective bridge branch of a measuring bridge having a bridge diagonal which is led to a first differential amplifier. A current in the bridge is adjusted in such a way that the sensor resistor always has a prescribed overtemperature. Due to backfires in the intake manifold, damage can occur to the sensor resistor due to sudden strong heating of the temperature detector resistor as a consequence of a strong rise in current. In order to avoid such damage, a third bridge branch is connected in parallel with the two bridge branches. The third bridge branch has a tap which is supplied, as is another tap, to inputs of a second differential amplifier having an output signal influencing the bridge current in such a way that the current is limited to a prescribed value. The device is applicable in internal combustion engines.

Abstract: An uncomplicated and reliable temperature sensor has a pair thermistors coupled in parallel with a current source that is connected in series with a load resistor. Temperature variations cause a robust current output change that generates a corresponding robust output voltage determined by a proper selection of the load resistor. Increased sensitivity is provided by the robust current to avoid many of the problems otherwise associated with D.C. amplifiers (e.g., drift).

Abstract: A method for thermal environment sensing utilizing superconducting materi finds utility in the production of low power cryogenic flow meters, bolometers, level detectors and other types of thermal environment sensors. A device for determining the first and second derivatives (dV/dI and d.sup.2 V/dI.sup.2) utilizes a ramped current until a set value of the first derivative (dV/dI) is achieved, the current supply being placed in a feedback mode to maintain the first derivative constant and monitoring any changes in the second derivative (d.sup.2 V/dI.sup.2) which indicate changes in the thermal environment. Alternatively, the second derivative is maintained constant and the first derivative is measured. Any parameter which is indicative of the non-linearity of the relationship between the voltage and the current can be utilized instead of the second derivative.

Abstract: The temperature measuring circuit includes a plurality of temperature sensors, each of which is formed by a temperature-dependent measuring resistance having two current terminals and two voltage tapping terminals arranged in each case between an associated current terminal and the temperature-dependent measuring resistance. The temperature sensors are connected via the current terminals in series and the series circuit is connected via two current conductors to an evaluating circuit which sends a constant current through the measuring resistances connected in series. For measuring the voltage drops caused by the constant current at the individual measuring resistances the voltage tapping terminals of each temperature sensor are connected by voltage conductors to the evaluating circuit. The two voltage tapping terminals of two temperature sensors following each other in the series circuit and assigned to two interconnected current terminals are each connected via a resistance to a common voltage conductor.

Abstract: A thermoresistive sensor system compensates for ambient temperature of a medium. First and second side-by-side sensors are mounted in the medium, each having a resistance that varies with temperature change in the medium. A thermal compensation control circuit supplies current to the first sensor such that the cube of its current times its resistance (I.sub.1.sup.3 .times.R.sub.1) is constant. The control circuit supplies current to the second sensor at a multiple of the current through the first sensor. A signal based upon the voltages across each sensor is produced as a temperature compensated output. In this manner, the system automatically compensates for temperature changes in the medium which would otherwise degrade the accuracy of the output.

Abstract: A system and method for calibrating a transducer having a bridge-type network. The calibration includes a source of constant current and a calibration circuit including the source connected across one of the resistive-type transducer elements of the bridge. Switching means are provided in the calibration circuit so that the current can be selectively supplied to or withheld from the resistive-type transducer element across which the calibration circuit means is connected for producing a calibration signal. The calibration signal is substantially independent of the transducer output regardless of whether or not the signal is temperature compensated and whether it is switched mechanically, electromechanically, or electrically. An internal calibration resistor in the current source is used to make the current inversally proportional to the bridge arm resistance. The calibration resistor tracks the resistive-type transducer elements of the bridge over temprature.

Abstract: Electronic circuit arrangement in a temperature measurement circuit based on a platinum resistor (PT) as a temperature sensing resistor, whereby in addition to the platinum resistor there is provided a reference resistor (R1). The measurement circuit (S) is adapted to apply equally large DC currents (I5, I6) to both resistors having a common return lead (3) from these, and to sense the resulting voltage difference (U) across the resistors. By means of at least one operational amplifier (G) the voltage difference is adapted to cause an output DC current from the measurement circuit (S) being proportional to the voltage diffeerence and thereby constituting a measure of the temperature of the platinum resistor (PT). The measurement circuit (S) comprises means (L) for compensating for non-linearity of the temperature-resistance characteristic of the platinum resistor.

Abstract: Integrated semiconductor circuit for thermal measurements, comprising at least a thermal signal comparator (8), the comparator (8) being provided with a signal feedback loop containing a DA signal converter (3), more specifically, the comparator (8) being a temperature or a heat current comparator, the DA signal-converter (3) comprising a thermal output and the signal feedback loop comprising components for the transfer of thermal signals.

Abstract: The monitoring device is constructed in such a way that the temperature measurement takes place directly at the bearing and there is no need for detaching connecting lines during changing of rolls. The main features of the monitoring device for roll bearings, installed, for example, in the chock (1) of the work roll (3) of a roll stand, reside in a thermal limit value pickup (6) in contact with the roll bearing (7), as well as in a mechanical, spring-loaded transmission member (8) locked in place in the chock (1) by way of the limit value pickup, for acting on a signal generator (9) arranged outside of the chock (1) in the roll stand, this signal generator being actuated to shut down the rolling mill by automatic outward movement of the transmission member (8) after releasing its locking device by the limit value pickup (6) upon reaching a limit temperature of the roll bearing (7). The monitoring device is preferably intended for use in thin-gage strip and foil rolling mills having high rolling speeds.

Abstract: Full-range temperature indicators used for the display of a temperature scale represented by the number of lamps illuminated based on the temperature of a thermocouple being detected by IC amplifier circuitry, diodes, switching transistors trigger-driven by contacts, illuminating a proper number of indicating lamps for a showing of the detected temperture. Also a particular range of temperature can be preset at upper and lower limits by a rheostat for sequential flashing of the indicating lamps around the limits set.

Abstract: The calibrator of an ohmmeter is compensated to eliminate any error as a result of the resistance of leads interconnecting terminals of the ohmmeter and a reference resistance to which the ohmmeter is connected during calibration. In accordance with one aspect of the invention, ohmmeter current flowing through a buffer amplifier biased by a floating power supply bypasses the ohmmeter leads. In accordance with another aspect, a current equal in magnitude but opposite in direction to the ohmmeter current is applied to the leads.

Abstract: An improved SCUBA diving gauge. A pictograph display is provided which has a shape which conveys the type of information being displayed. The pictograph has the shape of a SCUBA tank for a tank pressure display and the shape of a person for a display of nitrogen absorbed. Pressure transducers coupled to the SCUBA tank and the external water provided the pressure readings required to produce the respective displays. The differential signal from the transducer is supplied to a processor through an auto-zeroing circuit. The auto-zeroing circuit uses a capacitor initially coupled to an amplifier reference input and single ended output to store an offset voltage. During a measurement, the capacitor is disconnected from the amplifier output and has its other lead coupled to a full scale value of the differential input to produce an output signal which is a ratio.

Abstract: A temperature sensor which is flush mounted on a wall of a room in which the temperature is sensed. A mounting plate secured to the wall has a cavity in its face which receives an aluminum sensor plate and an insulating block which thermally insulates the sensor plate from the mounting plate. A temperature sensing integrated circuit contacts the back side of the sensor plate and has electrical leads which extend to the back side of a printed circuit board mounted in a pocket on the back side of the mounting plate. The integrated circuit acts as a current source having its output signal enhanced by active solid state circuit components mounted on the back side of the circuit board where their heat is dissipated by conduction through the mounting plate and wall and by convection and radiation into the wall cavity to avoid affecting the sensor plate. The circuitry allows active factory calibration and eliminates adverse effects on the signal caused by background environmental noise.