電(dian)壓(ya)變送器是將被測主(zhu)回路交流電(dian)壓(ya)或者(zhe)直流電(dian)壓(ya)信(xin)(xin)號(hao)轉(zhuan)換(huan)成按線性比例輸出的標(biao)準4～20mAdc信(xin)(xin)號(hao)或者(zhe)其(qi)他工業現(xian)場需要的信(xin)(xin)號(hao)，并將信(xin)(xin)號(hao)傳輸到(dao)接收(shou)裝置。 電(dian)壓(ya)(ya)變送(song)(song)器(qi)(qi)分(fen)直(zhi)流(liu)和交(jiao)流(liu)二種(zhong)。直(zhi)流(liu)電(dian)壓(ya)(ya)變送(song)(song)器(qi)(qi)是一種(zhong)能將被測交(jiao)流(liu)電(dian)壓(ya)(ya)轉(zhuan)化成按線(xian)形占(zhan)比輸出交(jiao)流(liu)電(dian)壓(ya)(ya)或直(zhi)流(liu)電(dian)流(liu)的(de)儀器(qi)(qi)設備，也廣泛運用在電(dian)力工程、實(shi)時(shi)監控(kong)、儀表設備、醫療器(qi)(qi)械、工業生產自動化控(kong)制(zhi)等(deng)每個必(bi)須用電(dian)量防(fang)護測控(kong)的(de)制(zhi)造行業。
交(jiao)流(liu)電(dian)(dian)(dian)壓變送器是一種能(neng)將被測交(jiao)流(liu)電(dian)(dian)(dian)流(liu)轉化成(cheng)(cheng)按線形占比輸出交(jiao)流(liu)電(dian)(dian)(dian)壓或直(zhi)流(liu)電(dian)(dian)(dian)流(liu)的儀器設備，廣泛運(yun)用于電(dian)(dian)(dian)力工程、電(dian)(dian)(dian)力、原油、煤碳、冶金(jin)工業(ye)、鐵(tie)路、市政工程等單(dan)位的電(dian)(dian)(dian)氣(qi)裝置、自動(dong)控制系統(tong)及其智能(neng)監控系統(tong)。溝通(tong)交(jiao)流(liu)智能(neng)變送器具備單(dan)相電(dian)(dian)(dian)、三(san)相組成(cheng)(cheng)結(jie)構形式。
電壓變(bian)送器的優(you)越(yue)性
1、不易受寄(ji)生熱(re)電(dian)偶和(he)沿(yan)電(dian)線(xian)(xian)電(dian)阻壓(ya)降和(he)溫漂(piao)的影響(xiang)，傳輸線(xian)(xian)可(ke)用非常(chang)便宜的更細(xi)的雙(shuang)絞線(xian)(xian)導線(xian)(xian);
2、在電(dian)(dian)流(liu)源輸出(chu)電(dian)(dian)阻足(zu)夠大(da)時，經磁場耦合感應到導(dao)線環(huan)路內的電(dian)(dian)壓(ya)，不會(hui)產生顯(xian)著影響，因為干擾(rao)源引起的電(dian)(dian)流(liu)極小，一般(ban)利(li)用雙(shuang)絞(jiao)線就能抵抗降(jiang)低(di)干擾(rao);
3、電(dian)容性干擾(rao)會導致接(jie)收器電(dian)阻有(you)關誤差，對于4～20mA兩線制環路，接(jie)收器電(dian)阻通常為(wei)250Ω(取樣Uout=1～5V)這個(ge)電(dian)阻小到不足以產生顯(xian)著誤差，因此，可以允(yun)許的(de)電(dian)線長度(du)比電(dian)壓(ya)遙(yao)測系統(tong)更長更遠;
4、各(ge)個(ge)單臺示(shi)讀裝置(zhi)或記錄裝置(zhi)可以(yi)在電(dian)線長度不等(deng)的不同通道間進行換(huan)接，不因電(dian)線長度的不等(deng)造成精度的差異;
5、將4mA用于零電平(ping)，使判斷開(kai)路或傳感器損(sun)壞(0mA狀態)十分(fen)方便。
6、 在兩(liang)線輸(shu)出(chu)口容易(yi)增設防浪涌(yong)和防雷器(qi)件，有(you)利于安全防雷防爆。
