基于单片机的热电偶测温系统的设计

《》(SOC)2009258-2360/：82-946《200》TheDesignofThermocoupleTemperatureMeasurementSystemBasedonSCM（）JINGHai-xiaZHOULin-boWANGRen-daoLIAONa:,,。,。/AD7705、,,/AD421/4mA~20mA,。:;;AD;DA;:TP273:AAbstract:Thermocoupleisusedfrequentlyinhigh-temperaturetestinthemodernizedindustryscene,thenthetestresultsaredeliv-eredtomastercontrolmachine.Asthenon-linearrelationshipbetweenthermoelectricpotentialandtemperature,itmustbecarriedoutonthethermocouplelinearprocessinginordertomaintainaccuracyoftest.Thisarticleisforthelinearizationofthermocouple.Thegeneralideaistostudyhigh-precisionA/DconverterAD7705,whichsamplesandenlargesthethermoelectricpotentialfromthethermocouple,touseacertainalgorithmforthelinearizationprocessinginthemicrocontroller,andtoconvertthedatatoproducethe4mA-20mAcurrentthroughhighprecisionA/DconverterAD421.Keywords:Thermocouple;Linearization;ADconversion;DAconversion;Single-chip-micro-computer:1008-0570(2009)08-2-0088-021、、、、、、。、。A/DD/A。/AD7705/AD421、、AD“”。1/1000。2STC89C52。1。。/16ADAD7705/DAAD421AD421AD42116/DA4mA-20mA。12.1/2AD/16、、、/AD7705。AD7705AD16∑－ΔA/DPGA、∑－ΔA/D。、、。、、:88--：82-946360/《PLC200》AD584AD7705AD7705。/2。2.2/16/AD421。AD421AD(DAC)164-20mA。AD421+5V+3.3V+3V+1.25V+2.5V。AD421Σ-ΔDAC16±0.001%±0.1%±0.2%10Mbps。DA。3。3DA3。1A/D、。2。3D/A。“”“”。。4。4DA4K。KAD7705/,AD421/。1‰。5STC89C52AD7705A/DAD421D/A“”、、。1‰。。[1].(3)[M].:,2007.6[2],,.[M].:,2007[3],.[J].,1999,12:23-25[4]．J．2008,6-2119-120:1976-2003。、、。Biography:JINGHai-xia(1976-),female,borninWanrongofShanxiProvince,receivedtheMaster’sdegreeinNorthWesternPolytechnicalUniversity,lectureofXi’anInternationalUniversi-ty,engagedintheteachingandscientificreseachofelectroniccircuits,signalsandsystemsanddatafusion（710077）（CollegeofInformationEngineering，Xi’anInternationalUniversity，Xi’anShanxi，710077，China）JINGHai-xiaZHOULin-boWANGRen-daoLIAONa：（710077（））(:2009.07.05)(:2009.08.05)bkxy??89--