從(cong)煉(lian)油(you)(you)廠到(dao)自動售貨機等工(gong)業(ye)(ye)應用(yong)(yong)要求具有精確的(de)溫(wen)度(du)、壓力(li) 和流量(liang)測量(liang)，以(yi)控制(zhi)復雜(za)以(yi)及(ji)簡單過程。例(li)如(ru)，在(zai)食品行業(ye)(ye)，產品裝瓶和裝罐(guan)(guan)的(de)流量(liang)精確控制(zhi)會直(zhi)接影響(xiang)利潤，因此必須(xu)較大(da)程度(du)降低(di)流量(liang)測量(liang)誤差。類似地(di)，封閉運輸應用(yong)(yong)——比(bi)如(ru)石油(you)(you)工(gong)業(ye)(ye)中油(you)(you)罐(guan)(guan)和油(you)(you)罐(guan)(guan)車(che)之間的(de)原油(you)(you)和成品油(you)(you)交(jiao)換——需要高精度(du)測量(liang)。

電磁流量(liang)計(ji)也能提供無創檢測(ce)。這些設(she)備可用于酸性(xing)、堿性(xing)和離子液(ye)體——這些液(ye)體的(de)(de)電導率(lv)范圍(wei)為(wei) 10 S/m至(zhi) 10–6 S/m，并(bing)且(qie)(qie)可以是(shi)干(gan)凈、骯臟(zang)、腐蝕(shi)性(xing)、侵蝕(shi)性(xing)或粘性(xing)的(de)(de)液(ye)體或漿體，但不適用于碳(tan)氫化合物或氣體流量(liang)測(ce)量(liang)。它們能夠(gou)針對直徑小(xiao)至(zhi)大約(yue) 0.125 英寸、最大容量(liang)為(wei) 10 立(li)方英尺的(de)(de)低(di)流速和高(gao)流速提供相對較高(gao)的(de)(de)系統(tong)精(jing)度(du)(0.2%)，并(bing)且(qie)(qie)哪怕(pa)在更低(di)的(de)(de)流速下(xia)(xia)也能保持讀數的(de)(de)可重復性(xing)。它們可以測(ce)量(liang)雙(shuang)向流量(liang)，即上游(you)或下(xia)(xia)游(you)。

電(dian)(dian)磁(ci)流量(liang)計采用法(fa)拉第電(dian)(dian)磁(ci)感應(ying)定律，該定律指(zhi)出，在磁(ci)場(chang)中移動的(de)(de)導體(ti)(ti)將會產生感應(ying)電(dian)(dian)壓(ya)。液體(ti)(ti)可(ke)看(kan)作導體(ti)(ti)；磁(ci)場(chang)由流管(guan)外(wai)的(de)(de)通電(dian)(dian)線圈(quan)產生。感應(ying)電(dian)(dian)壓(ya)幅度直接與導體(ti)(ti)的(de)(de)運動速(su)度和(he)導體(ti)(ti)類型(xing)、流管(guan)直徑以及磁(ci)場(chang)強(qiang)度成正比。流過(guo)勵(li)(li)磁(ci)線圈(quan)的(de)(de)電(dian)(dian)流產生受控磁(ci)場(chang)。專(zhuan)用勵(li)(li)磁(ci)波形是電(dian)(dian)磁(ci)流量(liang)計的(de)(de)一(yi)個重要方面，在實際應(ying)用中會使用多種類型(xing)，包括低頻(pin)(pin)矩形波、電(dian)(dian)力(li)線頻(pin)(pin)率正弦波、雙(shuang)頻(pin)(pin)波和(he)可(ke)編(bian)程脈(mo)沖寬度。

電(dian)(dian)(dian)(dian)(dian)(dian)磁流(liu)量(liang)計的(de)(de)(de)(de)勵(li)磁電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)相比其他流(liu)量(liang)測(ce)量(liang)技術(shu)而言非常大(da)，其范圍為(wei) 125 mA至 250 mA，覆蓋(gai)線(xian)路供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)式流(liu)量(liang)計的(de)(de)(de)(de)主要范圍。高(gao)(gao)達 500 mA或(huo) 1 A的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)將用于直徑更大(da)的(de)(de)(de)(de)管(guan)(guan)(guan)道。圖(tu) 4所示(shi)電(dian)(dian)(dian)(dian)(dian)(dian)路可以產(chan)生精密 250 mA傳(chuan)感器(qi)線(xian)圈(quan)勵(li)磁。8 ppm/°C基準電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)源(yuan)(yuan)ADR3412 提供(gong)實現電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)偏置的(de)(de)(de)(de) 1.2 V設定點(dian)。雖然這種(zhong)傳(chuan)統(tong)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)勵(li)磁方(fang)(fang)法(fa)采用基準電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)源(yuan)(yuan)、放大(da)器(qi)和晶體管(guan)(guan)(guan)電(dian)(dian)(dian)(dian)(dian)(dian)路提供(gong)良好(hao)的(de)(de)(de)(de)低噪聲性能，但該(gai)(gai)方(fang)(fang)法(fa)由(you)于經過功(gong)率晶體管(guan)(guan)(guan)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)和其兩(liang)端的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)降(jiang)都(dou)很(hen)大(da)，因(yin)此功(gong)率損失極(ji)大(da)。該(gai)(gai)方(fang)(fang)法(fa)需要使(shi)用散熱器(qi)，從而增加了系統(tong)成本和尺寸(cun)。具有開關(guan)模式電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)的(de)(de)(de)(de)恒(heng)流(liu)源(yuan)(yuan)正成為(wei)更流(liu)行的(de)(de)(de)(de)傳(chuan)感器(qi)線(xian)圈(quan)勵(li)磁方(fang)(fang)法(fa)。功(gong)率更高(gao)(gao)的(de)(de)(de)(de)系統(tong)采用電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)檢(jian)(jian)測(ce)診斷(duan)功(gong)能監測(ce)隨負載、電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)、時(shi)間和溫度變化(hua)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)改變，同時(shi)還能檢(jian)(jian)測(ce)傳(chuan)感器(qi)線(xian)圈(quan)開路。電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)或(huo)檢(jian)(jian)測(ce)元件同樣也是重要的(de)(de)(de)(de)考慮(lv)因(yin)素(su)。兩(liang)種(zhong)主要的(de)(de)(de)(de)測(ce)量(liang)技術(shu)都(dou)是容性的(de)(de)(de)(de)，一(yi)種(zhong)是電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)安裝在管(guan)(guan)(guan)道外(wai)面；另一(yi)種(zhong)更常見，即電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)插入管(guan)(guan)(guan)道中，并(bing)由(you)液體沖刷。

如果兩個電(dian)極(ji)(ji)(ji)采用(yong)相(xiang)同(tong)的(de)材料，并(bing)且具有相(xiang)同(tong)的(de)表面狀況(kuang)，那么(me)它們的(de)電(dian)位應當相(xiang)等。然而，事實上，極(ji)(ji)(ji)化電(dian)位會像低頻交(jiao)流(liu)信號(hao)那樣緩慢波動，因為(wei)(wei)流(liu)體和電(dian)極(ji)(ji)(ji)之間存在物理摩擦(ca)或電(dian)化學(xue)效應。任何失配都將表現為(wei)(wei)差模(mo)噪聲(sheng)。偏置電(dian)壓與電(dian)極(ji)(ji)(ji)電(dian)位共(gong)(gong)(gong)同(tong)組成共(gong)(gong)(gong)模(mo)電(dian)壓，在第一級放大器輸入(ru)端(duan)產(chan)生幾百mV至大約1 V的(de)共(gong)(gong)(gong)模(mo)電(dian)壓；因此，電(dian)子器件(jian)必須(xu)具有適(shi)當的(de)共(gong)(gong)(gong)模(mo)抑制能(neng)力。

ADI的高(gao)效率DC-DC調節器、集成式(shi)通信、高(gao)分(fen)辨率ADC、精密放大器以及高(gao)精度基準(zhun)電壓源(yuan)可(ke)讓(rang)設(she)計人員(yuan)實現新設(she)計，并 獲得高(gao)于這些要求的性能(neng)。