|
電磁流量計這種測量儀器的選材是需要很多驗證的,下麵我們就為大家介紹一下電磁流量計電極與接地環材料選擇的小知識。
1)選擇耐腐蝕材料LDE電極的耐腐蝕性要求很高,常用金屬材料有含鉬耐酸鋼Icr18Ni12Mo2Ti,哈氏合金(耐蝕鎳基合金)B、C、鈦、鉭、鉑銥合金,幾乎可覆蓋全部化學液。此外還有適用於漿液等的低噪聲電極,它們是導電橡膠電極、daodianfusuliaodianjiheduokongxingtaocidianji,huobaofuzhexiecailiaodejinshudianji。zaiyuanzeshangdianjicailiaodexuanzeyingcongshiyongzhejiejiangaijiezhizaiqitashebeideyingyongshijiheyiwangdejingyanlaiqueding。youshihouyaozuobiyaodeshiyan,ruxianchangquyetiyangpinzaishiyanshizuodaiyongcailiaodefushixingshiyan。zuihaodeshiyanshixianchangguapian,zheshizuijiejinshijiyingyongtiaojiandefushixingshiyan,keyidechubijiaokekaonengfoushiyongdejielun。
2)避(bi)免(mian)電(dian)極(ji)表(biao)麵(mian)效(xiao)應(ying)電(dian)極(ji)的(de)耐(nai)腐(fu)蝕(shi)性(xing)是(shi)選(xuan)擇(ze)材(cai)料(liao)的(de)重(zhong)要(yao)因(yin)素(su),但(dan)有(you)時(shi)候(hou)電(dian)極(ji)材(cai)料(liao)對(dui)被(bei)測(ce)介(jie)質(zhi)有(you)很(hen)好(hao)的(de)耐(nai)腐(fu)蝕(shi)性(xing),卻(que)不(bu)一(yi)定(ding)就(jiu)是(shi)適(shi)用(yong)的(de)材(cai)料(liao),還(hai)要(yao)避(bi)免(mian)產(chan)生(sheng)電(dian)極(ji)表(biao)麵(mian)效(xiao)應(ying)。
電極表麵效應分為表麵化學反應、電化學和極化現象以及電極的觸媒作用三個方麵。
a化(hua)學(xue)反(fan)應(ying)效(xiao)應(ying)如(ru)電(dian)極(ji)表(biao)麵(mian)與(yu)被(bei)測(ce)介(jie)質(zhi)接(jie)觸(chu)後(hou),形(xing)成(cheng)鈍(dun)化(hua)膜(mo)或(huo)氧(yang)化(hua)層(ceng)。他(ta)們(men)對(dui)耐(nai)腐(fu)蝕(shi)性(xing)能(neng)可(ke)能(neng)起(qi)到(dao)積(ji)極(ji)保(bao)護(hu)作(zuo)用(yong),但(dan)也(ye)有(you)可(ke)能(neng)增(zeng)加(jia)表(biao)麵(mian)接(jie)觸(chu)電(dian)阻(zu)。例(li)如(ru)鉭(tan)與(yu)水(shui)接(jie)觸(chu)就(jiu)會(hui)被(bei)氧(yang)化(hua),生(sheng)成(cheng)絕(jue)緣(yuan)層(ceng)。
b對於避免或減輕電極表麵效應的介質――電極材料匹配,還沒有像腐蝕性那樣有充足的資料可查,隻有一些有限經驗,尚待在實踐中積累。
cjiedihuanlianjiezaisuliaoguandaohuochenjueyuanchenlijinshuguandaodeliuliangchuanganqiliangduan,tamendenaifushiyaoqiubidianjidi,chongfenyouyidingfushi,dingqigenghuan。tongchangxuanyongnaisuanganghuohashihejin。yintijidacongjingjishangkaolvjiaoshaocaiyongtanbodengguizhongjinshu。rujinshugongyiguandaozhijieyuliutijiechujiubuxuyaojiedihuan。
|