福彩快三

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热电偶温度传感器测量误差的主要影响因素

发布时间:2019-9-3      发布人:泽天传感      点击:

1 插入深度的影响

福彩快三 1)CEWENDIANDEXUANZE,REDIANOUWENDUCHUANGANQIDEANZHUANGWEIZHI,JICEWENDIANDEXUANZESHIZUIZHONGYAODE。CEWENDIANDEWEIZHI,DUIYUSHENGCHANGONGYIGUOCHENGERYAN,YIDINGYAOJUYOUDIANXINGXING、DAIBIAOXING,FOUZEJIANGSHIQUCELIANGYUKONGZHIDEYIYI。

2)CHARUSHENDU,REDIANOUWENDUCHUANGANQICHARUBEICECHANGSUOSHI,YANZHEWENDUCHUANGANQIDEZHANGDUFANGXIANGJIANGCHANSHENGRELIU。DANGHUANJINGWENDUDISHIJIUHUIYOURESUNSHI。ZHISHIREDIANOUYUBEICEDUIXIANGDEWENDUBUYIZHIERCHANSHENGCEWENWUCHA。ZONGZHI,YOURECHUANDAOERYINQIDEWUCHA,YUCHARUSHENDUYOUGUAN。ERCHARUSHENDUYOUYUBAOHUGUANCAIZHIYOUGUAN。JINSHUBAOHUGUANYINQIDAOREXINGNENGHAO,QICHARUSHENDUYINGGAISHENYIXIE(YUEWEIZHIJINGDE15—20BEI),TAOCICAILIAOJUEREXINGNENGHAO,KECHARUQIANYIXIE(YUEWEIZHIJINGDE10-15BEI)。DUIYUGONGCHENGCEWEN,QICHARUSHENDUHAIYUCELIANGDUIXIANGSHIJINGZHIHUOLIUDONGDENGZHUANGTAIYOUGUAN,RULIUDONGDEYETIHUOGAOSUQILIUWENDUDECELIANG,JIANGBUSHOUSHANGSHUXIANZHI,CHARUSHENDUKEYIQIANYIXIE,JUTISHUZHIYINGYOUSHIYANQUEDING。

2 响应时间的影响

JIECHUFACEWENDEJIBENYUANLISHICEWENYUANJIANYAOYUBEICEDUIXIANGDADAOREPINGHENG。YINCI,ZAICEWENSHIXUYAOBAOCHIYIDINGSHIJIAN,CAINENGSHILIANGZHEDADAOREPINGHENG。ERBAOCHISHIJIANDEZHANGDUAN,TONGCEWENYUANJIANDEREXIANGYINGSHIJIANYOUGUAN。ERREXIANGYINGSHIJIANZHUYAOQUJUEYUCHUANGANQIDEJIEGOUJICELIANGTIAOJIAN,CHABIEJIDA。DUIYUQITIJIEZHI,YOUQISHIJINGZHIQITI,ZHISHAOYINGBAOCHI30minYISHANGCAINENGDADAOPINGHENG;DUIYUYETIERYAN,ZUIKUAIYEYAOZAI5FENZHONGYISHANG。

DUIYUWENDUBUDUANBIANHUADEBEICECHANGHE,YOUQISHISHUNJIANBIANHUAGUOCHENG,QUANGUOCHENGJIN1MIAOZHONG,ZEYAOQIUCHUANGANQIDEXIANGYINGSHIJIANZAIHAOMIAOJI。YINCI,PUTONGDEZETIANWENDUCHUANGANQIBUJINGENBUSHANGBEICEDUIXIANGDEWENDUBIANHUASUDUCHUXIANZHIHOU,ERQIEYEHUIYINDABUDAOREPINGHENGERCHANSHENGCELIANGWUCHA。ZUIHAOXUANZEXIANGYINGKUAIDECHUANGANQI。DUIREDIANOUERYANCHUBAOHUGUANYINGXIANGWAI,REDIANOUDECELIANGDUANZHIJINGYESHIQIZHUYAOYINSU,JIOUSIYUEXI,CELIANGDUANZHIJINGYUEXIAO,QIREXIANGYINGSHIJIANYUEDUAN。CEWENYUANJIANREXIANGYINGWUCHAKETONGGUOXIASHIQUEDING。

Δθ=Δθ0exp(-t/τ)               (1)

福彩快三 SHIZHONGt—CELIANGSHIJIANS,Δθ—ZAItSHIKE,CEWENYUANJIANYINQIDEWUCHA,KHUO℃;Δθ0—“t=0”SHIKE,CEWENYUANJIANYINQIDEWUCHA,KHUO℃;τ—SHIJIANCHANGSHUS;e —ZIRANDUISHUDEDI(2.718);YINCI,DANGt=τSHI,ZEΔθ=Δθ0/e  JIWEI0.368,RUGUODANGt=2τSHI,ZEΔθ=Δθ0/e2JIWEI0.135。

DANGBEICEDUIXIANGDEWENDU,YIYIDINGDESUDUα(k/sHUO℃/s)SHANGSHENGHUOXIAJIANGSHI,JINGGUOZUGOUDESHIJIANHOU,SUOCHANSHENGDEXIANGYINGWUCHAKEYONGXIASHIBIAOSHI:

Δθ∞=-ατ                            (2)

SHIZHONG  Δθ∞—JINGGUOZUGOUSHIJIANHOU,CEWENYUANJIANYINQIDEWUCHA。

YOUSHI(2)KEYIKANCHU,XIANGYINGWUCHAYUSHIJIANCHANGSHU(τ)CHENGZHENGBI。WEILETIGAOJIANDINGXIAOLVXUDUOQIYECAIYONGZETIANCHUANGANZIDONGJIANDINGZHUANGZHI,DUIRUCHANGREDIANOUJINXINGJIANDING,DANSHI,GAIZHUANGZHIYEBINGFEISHIFENWANSHAN。ERQIBIANSUXIANGCHANGRECHULICHEJIANJIUFAXIANRUGUOZAI400℃DIANDEHENGWENSHIJIANBUGOU,DABUDAOREPINGHENG,JIURONGYIFASHENGWUPAN。

3 热辐射的影响

福彩快三 CHARULUNEIYONGYUCEWENDEREDIANOU,JIANGBEIGAOWENWUTIFACHUDEREFUSHEJIARE。JIADINGLUNEIQITISHITOUMINGDE,ERQIE,REDIANOUWENDUCHUANGANQIYULUBIDEWENCHAJIAODASHI,JIANGYINNENGLIANGJIAOHUANERCHANSHENGCEWENWUCHA。

福彩快三 ZAIDANWEISHIJIANNEI,LIANGZHEJIAOHUANDEFUSHENENGWEIP,KEYONGXIASHIBIAOSHI:

福彩快三 P=σε(Tw4 - Tt4)            (3)

福彩快三 SHIZHONGσ—SITEFAN—BOERZICHANGSHU;ε—FASHELV;Tt—REDIANOUDEWENDU, K;Tw—LUBIDEWENDU, K

ZAIDANWEISHIJIANNEI,REDIANOUTONGZHOUWEIDEQITI(WENDUWEIT),TONGGUODUILIUJIRECHUANDAOYEJIANGFASHENGRELIANGJIAOHUANDENENGLIANGWEIP′

P′=αA(T-Tt)                  (4)

SHIZHONGα—REDAOLV;A—REDIANOUDEBIAOMIANJI;ZAIZHENGCHANGZHUANGTAIXIA,P= P′,QIWUCHAWEI:

福彩快三 Tt-T=σε(Tt4-Tw4)/αА     (5)

福彩快三 DUIYUDANWEIMIANJIERYANQIWUCHAWEI

Tt-T=σε(Tt4-Tw4)/α       (6)

福彩快三 YINCI,WEILEJIANSHAOREFUSHEWUCHA,YINGZENGDARECHUANDAO,BINGSHILUBIWENDUTw,JINKENENGJIEJINREDIANOUDEWENDUTt。LINGWAI,ZAIANZHUANGSHIHAIYINGZHUYI:REDIANOUANZHUANGWEIZHI,YINGJINKENENGBIKAICONGGUTIFACHUDEREFUSHE,SHIQIBUNENGFUSHEDAOREDIANOUBIAOMIAN;REDIANOUZUIHAODAIYOUREFUSHEZHEBITAO。

4 热阻抗增加的影响

在高温下使用的热电偶温度传感器,如果被测介质为气态,那么保护管表面沉积的灰尘等将烧熔在表面上,使保护管的热阻抗增大;如果被测介质是熔体,在使用过程中将有炉渣沉积,不仅增加了热电偶的响应时间,而且还使指示温度偏低。因此,除了定期检定外,为了减少误差,经常抽检也是必要的。例如,进口铜熔炼炉,不仅安装有连续测温热电偶,还配备消耗型热电偶测温装置,用于及时校准连续测温用热电偶的准确度。