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Non-electrical signal to the sensor signals into the circuit a total follow-up measurement and analysis， measurement and control system is an indispensable component， it is the nature of various non-electrical signal conversion and signal mutual In the monitoring and control system， the quality and characteristics of the sensor affect the performance of the entire Temperature measurement in the area of negative temperature coefficient (NTC) thermistor in its response has been fast and wide measurement range， the advantages of cheap occupy certain market However， different series of thermistor resistance difference between the thermistor and the same series of individual differences seriously affect the actual use of the Subject to the single-chip microcomputer as the core design of AVR NTC temperature characteristics tester， in the design of high-precision temperature sensor PT100 thermal resistance of the heating environment in which real-time accurate measurement， the use of constant current source circuit as a sensor drive circuit， through the TLC2543 to be the temperature of high-speed data At the same time bridge the use of constant current source of the resistance of the thermistor measured the output signal through the bridge with the PGA-type △ ∑ A / D converter AD7705 is converted to digital From these single-chip temperature， the corresponding value recorded and the data sent through the serial port to the PC， in this way to measure the temperature characteristics of thermistor
Abstract:The sensor can transform the non-electric signal as the electrical signal altogether following electric circuit survey and the analysis， is observes and controls in the system the essential part， it is the link which nature each non-electric signal and the electrical signal transform In the observation system， sensor's quality and the characteristic are affecting the entire electric circuit's In the temperature survey domain， the negative temperature coefficient (NTC) thermistor has been quick by its reaction rate， merits and so on measuring range width， price small advantage are occupying certain market But between different series thermistor's resistance number difference and in same series thermistor's individual difference serious influence actual use this topic take the AVR monolithic integrated circuit as the core design negative temperature coefficient thermistor temperature characteristic reflectoscope reflector， uses the high accuracy in this design temperature sensor PT100 to locate the heating environment to the thermistor to carry on the real-time precision measuring， takes the sensor driving circuit using the constant current electric circuit， obtains the temperature data through the TLC2543 high speed Simultaneously uses the constant current electric bridge to carry on the survey to thermistor's resistance number， the electric bridge output signal through has PGA △∑ A/D switch AD7705 to transform into the digital By the monolithic integrated circuit these temperatures， the resistance number correspondence's data record and transmits through the serial port for PC machine， surveys thermistor's temperature characteristic by this Key word: Monolithic integrated circuit; PT100; Constant current electric bridge; Measure of resistance 应该是这样！
Sensors can be transformed into the signal of subsequent signal circuit， measurement and analysis of measurement and control system is an indispensable part of nature， it is each signal and mutual transformation between the In the measurement system， the quality and characteristics of the sensor affects the entire circuit In temperature measurement field， negative temperature coefficient (NTC thermistors) has been the reaction speed， wide measuring range， price cheap holds certain advantages in the But different series resistance of the difference between thermistors and the same series thermistors individual differences of serious impact on the actual use of This topic in AVR singlechip design negative temperature coefficient thermistors temperature characteristics， in the design of test using high temperature sensor for thermistors 16pt100 in real-time accurate measurement of heating environment， use constant-current source circuit， drive circuit as the sensor TLC2543 through high-speed sampling get temperature At the same time constant-current source resistance to thermal resistor of bridge， the output signal measured by bridge with the train ∑ PGA type A/D converter AD7705 converts digital By single-chip microcomputer temperature， resistance to the corresponding data recorded by serial transmitted PC， this approach to measuring temperature characteristics of thermal Keywords: SCM， 16pt100， Constant-current source bridge， Resistance measurements
