電磁流量計的常見故障及維護保養
1 概述
電磁流量計是高精度、gaokekaoheshiyongshoumingchangdeliuliangyibiao，tacaiyongdanpianjiqianrushijishu，genjufaladidianciganyingdinglvlaiceliangguanneidaodianjiezhitijiliuliangdeganyingshiyibiao。xianyiguangfandiyingyongyuhuagong、環保、冶金、醫藥、電力、給排水等工業技術和管理部門。電磁流量計在滿足現場顯示的同時，還可以輸出4～20mA電流信號供記錄、調節和控製用。在設計產品結構、選材、製定工藝、shengchanzhuangpeihechuchangceshidengguochengzhongmeiyigehuanjiedoufeichangguanjian，duodianjijiegoubaozhengleceliangjingdubingqierenheshihouwuxujiedihuan，jianqingleyibiaotijiheanzhuangweihudemafan。dianciliuliangjijuyoudaibeiguangkuanwendezhongwenyejingxianshiqi，gongnengqiquanshiyong、顯示直觀、操作使用方便，可以減少其他電磁流量計英文菜單所帶來的不便。本文就電磁流量計的常見故障及日常的維護保養要點進行簡述。
2 電磁流量計的主要特點
2.1 能耗較低
dianciliuliangjidechuanganqijiegoujiandan，celiangguanneimeiyoukedongbujian，yemeiyourenhezuailiutiliudongdejieliubujian。suoyidangliutitongguoliuliangjishibuhuiyinqirenhefujiadeyalisunshi，shiliuliangjizhongyunxingnenghaozuidideliuliangyibiaozhiyi。
2.2 測量範圍廣泛
電磁流量計可測量贓汙介質、腐fu蝕shi性xing介jie質zhi及ji懸xuan濁zhuo性xing液ye固gu兩liang相xiang流liu的de流liu量liang。這zhe是shi由you於yu儀yi表biao測ce量liang管guan內nei部bu無wu阻zu礙ai流liu動dong部bu件jian，與yu被bei測ce流liu體ti接jie觸chu的de隻zhi是shi測ce量liang管guan內nei襯chen和he電dian極ji，其qi材cai料liao可ke根gen據ju被bei測ce流liu體ti的de性xing質zhi來lai選xuan擇ze。例li如ru，用yong聚ju三san氟fu乙yi烯xi或huo聚ju四si氟fu乙yi烯xi做zuo內nei襯chen，可ke測ce量liang各ge種zhong酸suan、堿、鹽等腐蝕性介質；渦街流量計采用耐磨橡膠做內襯，就特別適合於測量帶有固體顆粒的、磨損較大的礦漿、水泥漿等液固兩相流以及各種帶纖維液體和紙漿等懸濁液體。
2.3 不易受外界影響
電磁流量計是一種體積流量測量儀表，在測量過程中，它不受被測介質的溫度、粘度、密度以電導率的影響。因此，電磁流量計隻需經水標定後，在一定範圍，就可用來測量其它導電性液體的流量。
2.4 量程範圍寬
dianciliuliangjideshuchuzhiyubeicejiezhidepingjunliusuchengzhengbi，eryuduichengfenbuxiadeliudongzhuangtaiwuguan。suoyidianciliuliangjideliangchengfanweijikuan，qiceliangfanweidukeda100：1，有的甚至達1000：1的可運行流量範圍。
2.5 反應靈敏
電磁流量計無機械慣性，反應靈敏，可以測量瞬時脈動流量，也可測量正反兩個方向的流量。
2.6 口徑範圍寬
工業用電磁流量計的口徑範圍極寬，從幾個毫米一直到幾米，而且國內已有口徑達3m的實流校驗設備，為電磁流量計的應用和發展奠定了基礎。
3 電磁流量計的常見故障
3.1 儀表本身故障
儀表結構件或元器件損壞引起的故障。
3.2 外界原因引起的故障
3.2.1 調試期故障
調tiao試shi期qi故gu障zhang出chu現xian在zai新xin裝zhuang用yong後hou調tiao試shi初chu期qi，主zhu要yao原yuan因yin是shi儀yi表biao選xuan用yong或huo設she定ding不bu當dang，安an裝zhuang不bu妥tuo等deng。本ben類lei故gu障zhang在zai電dian磁ci流liu量liang計ji初chu始shi裝zhuang用yong調tiao試shi時shi就jiu出chu現xian，但dan一yi經jing改gai進jin排pai除chu故gu障zhang，以yi後hou在zai相xiang同tong條tiao件jian下xia一yi般ban就jiu不bu會hui再zai度du出chu現xian。常chang見jian調tiao試shi期qi故gu障zhang主zhu要yao有you安an裝zhuang不bu妥tuo、環境幹擾、liutitexingyingxiangsanfangmianyuanyin。diyi，guandaoxitongheanzhuangdengfangmian。tongchangshidianciliuliangchuanganqianzhuangweizhibuzhengqueyinqideguzhang，changjiandelirujiangliuliangchuanganqianzhuangzaiyijijuzhuliuqitideguanwanggaodian；流量傳感器後無背壓，孔板流量計液體逕直排人大氣，形成其測量管內非滿管；zhuangzaizishangxiangxialiudechuizhiguandaoshang，kenengchuxianpaikongdeng。dier，huanjingfangmian。zhuyaoshiguandaozasandianliuganrao，kongjiandianciboganrao，dadianjicichangganraodeng。guandaozasandianliuganraotongchangcaiqulianghaodandujiedibaohukehuodemanyiceliang，danruyuguandaoyouqiangzasandianliuyibuyidingnengkefu，xucaiquliuliangchuanganqiyuguandaoyuanjuedecuoshi。kongjiandianciboganraotongchangcaiyongdancenghuoduocengpingbiyuyibaohu，danyezengyudaopingbibaohuhaibunengkefu。disan，liutifangmian。yetihanyoujunyunfenbuxixiaoqipaotongchangbuyingxiangzhengchangceliang，weisuocedetijiliuliangshiyetiheqitiliangzhezhihe；氣泡增大會使輸出信號波動，若氣泡大到流過電極遮蓋整個電極表麵，使電極信號回路瞬時斷開，輸出信號將產生更大波動。低頻（50/16Hz-50/6Hz）矩(ju)形(xing)波(bo)激(ji)磁(ci)電(dian)磁(ci)流(liu)量(liang)計(ji)測(ce)量(liang)液(ye)體(ti)中(zhong)含(han)有(you)固(gu)體(ti)超(chao)過(guo)一(yi)定(ding)含(han)量(liang)時(shi)將(jiang)產(chan)生(sheng)漿(jiang)液(ye)噪(zao)聲(sheng)，輸(shu)出(chu)信(xin)號(hao)亦(yi)會(hui)有(you)一(yi)定(ding)程(cheng)度(du)波(bo)動(dong)。兩(liang)種(zhong)或(huo)兩(liang)種(zhong)以(yi)上(shang)液(ye)體(ti)作(zuo)管(guan)道(dao)混(hun)合(he)工(gong)藝(yi)時(shi)，若(ruo)兩(liang)種(zhong)液(ye)體(ti)電(dian)導(dao)率(lv)或(huo)各(ge)自(zi)與(yu)電(dian)極(ji)間(jian)電(dian)位(wei)有(you)差(cha)異(yi)，在(zai)混(hun)合(he)未(wei)均(jun)勻(yun)前(qian)即(ji)進(jin)入(ru)流(liu)量(liang)傳(chuan)感(gan)器(qi)進(jin)行(xing)流(liu)量(liang)測(ce)量(liang)，輸(shu)出(chu)信(xin)號(hao)亦(yi)會(hui)產(chan)生(sheng)波(bo)動(dong)。電(dian)極(ji)材(cai)質(zhi)與(yu)被(bei)測(ce)介(jie)質(zhi)選(xuan)配(pei)不(bu)善(shan)，產(chan)生(sheng)鈍(dun)化(hua)或(huo)氧(yang)化(hua)等(deng)化(hua)學(xue)作(zuo)用(yong)，電(dian)極(ji)表(biao)麵(mian)形(xing)成(cheng)絕(jue)緣(yuan)膜(mo)，以(yi)及(ji)電(dian)化(hua)學(xue)和(he)極(ji)化(hua)現(xian)象(xiang)等(deng)，均(jun)會(hui)妨(fang)礙(ai)正(zheng)常(chang)測(ce)量(liang)。
3.2.2 運行期故障
yunxingqiguzhangyibanzaiyunxingyiduanshiqihouchuxian，shidianciliuliangjijingchuqitiaoshibingzhengchangyunxingyiduanshiqihouzaiyunxingqijianchuxiandeguzhang，changjianguzhangdezhuyaoyuanyinyouliutizhongzazhifuzhedianjichenli，liuliangchuanganqineibifuzheceng，leidianji，huanjingtiaojianbianhuachuxianxinganraoyuandeng。diyi，neibifuzheceng。youyudianciliuliangjicelianghanyouxuanfuguxianghuowuzangtidejihuiyuanbiqitaliuliangyibiaoduo，chuxianneibifuzhecengchanshengdeguzhanggailvyejiuxiangduijiaogao。ruofuzhecengdiandaolvyuyetidiandaolvxiangjin，yibiaohainengzhengchangshuchuxinhao，zhishigaibianliutongmianji，xingchengceliangwuchadeyinxingguzhang；若是高電導率附著層，電極間電動勢將被短路；ruoshijueyuanxingfuzheceng，dianjibiaomianbeijueyuanerduankaiceliangdianlu。houliangzhongxianxiangjunhuishiyibiaowufagongzuo。dier，leidianji。leidianjizaixianluzhongganyingshunshigaodianyahelangyongdianliu，jinruyibiaojiuhuisunhuaiyibiao。leidianjisunyibiaoyousantiaoyinrutujing：電(dian)源(yuan)線(xian)，傳(chuan)感(gan)器(qi)勺(shao)轉(zhuan)換(huan)器(qi)間(jian)的(de)流(liu)量(liang)信(xin)號(hao)線(xian)和(he)激(ji)磁(ci)線(xian)。然(ran)而(er)從(cong)雷(lei)電(dian)故(gu)障(zhang)中(zhong)損(sun)壞(huai)零(ling)部(bu)件(jian)的(de)分(fen)析(xi)，引(yin)起(qi)故(gu)障(zhang)的(de)感(gan)應(ying)高(gao)電(dian)壓(ya)和(he)浪(lang)湧(yong)電(dian)流(liu)大(da)部(bu)分(fen)足(zu)從(cong)控(kong)製(zhi)室(shi)電(dian)源(yuan)線(xian)路(lu)引(yin)入(ru)的(de)，其(qi)他(ta)兩(liang)條(tiao)途(tu)徑(jing)較(jiao)少(shao)。還(hai)從(cong)發(fa)生(sheng)雷(lei)擊(ji)事(shi)故(gu)現(xian)場(chang)了(le)解(jie)到(dao)，不(bu)僅(jin)電(dian)磁(ci)流(liu)量(liang)計(ji)出(chu)現(xian)故(gu)障(zhang)，控(kong)製(zhi)室(shi)中(zhong)其(qi)他(ta)儀(yi)表(biao)電(dian)常(chang)常(chang)同(tong)時(shi)出(chu)現(xian)雷(lei)擊(ji)事(shi)故(gu)。因(yin)此(ci)使(shi)用(yong)單(dan)位(wei)要(yao)認(ren)識(shi)設(she)置(zhi)控(kong)製(zhi)室(shi)儀(yi)表(biao)電(dian)源(yuan)線(xian)防(fang)雷(lei)設(she)施(shi)的(de)重(zhong)要(yao)性(xing)。第(di)三(san)，環(huan)境(jing)條(tiao)件(jian)變(bian)化(hua)出(chu)現(xian)幹(gan)擾(rao)源(yuan)。主(zhu)要(yao)原(yuan)因(yin)與(yu)調(tiao)試(shi)期(qi)故(gu)障(zhang)環(huan)境(jing)方(fang)麵(mian)基(ji)本(ben)相(xiang)同(tong)，隻(zhi)是(shi)幹(gan)擾(rao)源(yuan)不(bu)在(zai)調(tiao)試(shi)期(qi)出(chu)現(xian)而(er)在(zai)運(yun)行(xing)期(qi)間(jian)再(zai)介(jie)入(ru)的(de)。例(li)如(ru)一(yi)台(tai)接(jie)地(di)保(bao)護(hu)並(bing)不(bu)理(li)想(xiang)的(de)電(dian)磁(ci)流(liu)量(liang)計(ji)，調(tiao)試(shi)期(qi)因(yin)無(wu)幹(gan)擾(rao)源(yuan)，儀(yi)表(biao)運(yun)行(xing)正(zheng)常(chang)，然(ran)而(er)在(zai)運(yun)行(xing)期(qi)出(chu)現(xian)新(xin)幹(gan)擾(rao)源(yuan)，測(ce)量(liang)點(dian)附(fu)近(jin)管(guan)道(dao)或(huo)較(jiao)遠(yuan)處(chu)實(shi)施(shi)管(guan)道(dao)電(dian)焊(han)，幹(gan)擾(rao)儀(yi)表(biao)正(zheng)常(chang)運(yun)行(xing)，出(chu)現(xian)輸(shu)出(chu)信(xin)號(hao)大(da)幅(fu)度(du)波(bo)動(dong)。
4 電磁流量計的維護保養
電dian磁ci流liu量liang計ji轉zhuan換huan器qi具ju有you自zi診zhen斷duan功gong能neng。除chu了le電dian源yuan和he硬ying件jian電dian路lu故gu障zhang外wai，一yi般ban應ying用yong中zhong出chu現xian的de故gu障zhang均jun能neng正zheng確que給gei出chu報bao警jing信xin息xi。這zhe些xie信xin息xi在zai顯xian示shi器qi右you下xia方fang給gei出chu相xiang應ying提ti示shi。電dian磁ci流liu量liang計ji常chang見jian故gu障zhang的de維wei護hu與yu保bao養yang主zhu要yao有you以yi下xia幾ji個ge方fang麵mian：
4.1 儀表無顯示
出chu現xian此ci故gu障zhang時shi，應ying首shou先xian檢jian查zha電dian源yuan是shi否fou接jie通tong，檢jian查zha電dian源yuan保bao險xian絲si是shi否fou完wan好hao，檢jian查zha供gong電dian電dian壓ya是shi否fou符fu合he要yao求qiu，如ru果guo上shang述shu都dou正zheng常chang，應ying將jiang轉zhuan換huan器qi送song與yu生sheng產chan廠chang家jia進jin行xing維wei修xiu。
4.2 勵磁報警
出現此現象時，應檢查勵磁接線x和y是否開路，檢查勵磁線圈電阻值是否正常，以此判定轉換器是否有故障。
4.3 空管報警
chuxianciwentishi，yingceliangliutishifouchongmanchuanganqiceliangguan，jianzhaxinhaolianxianshifouzhengque。jianzhaliuliangchuanganqidianjishifouzhengchang。yongdaoxianjiangzhuanhuanqixinhaoshuruduanzia、b和c三點短路，此時如果“空管報警”提示撤消，說明轉換器正常，有可能是被測流體電導率低或空管閾值及空管量程設置錯誤。
4.4 測量的流量不準確
出現此情況時，應檢測流體是否充滿傳感器測量管，信號線連接是否正常，檢查傳感器係數、傳感器零點是否按傳感器標牌或出廠校驗單設置正常。
