天康超聲波液位計

可采用(yong)二線(xian)(xian)制、三線(xian)(xian)制或四線(xian)(xian)制技術，二線(xian)(xian)制為：供(gong)電(dian)(dian)(dian)與信(xin)號(hao)(hao)輸出(chu)(chu)共(gong)用(yong)；三線(xian)(xian)制為：供(gong)電(dian)(dian)(dian)回路(lu)和(he)信(xin)號(hao)(hao)輸出(chu)(chu)回路(lu)獨立(li)，當(dang)采用(yong)直(zhi)流24v供(gong)電(dian)(dian)(dian)時，可使用(yong)一(yi)根3芯(xin)電(dian)(dian)(dian)纜線(xian)(xian)，供(gong)電(dian)(dian)(dian)負端和(he)信(xin)號(hao)(hao)輸出(chu)(chu)負端共(gong)用(yong)一(yi)根芯(xin)線(xian)(xian)；四線(xian)(xian)制為：當(dang)采用(yong)交流220v供(gong)電(dian)(dian)(dian)時，或者當(dang)采用(yong)直(zhi)流24v供(gong)電(dian)(dian)(dian)，要求供(gong)電(dian)(dian)(dian)回路(lu)與信(xin)號(hao)(hao)輸出(chu)(chu)回路(lu)*隔離時，應使用(yong)一(yi)根4芯(xin)電(dian)(dian)(dian)纜線(xian)(xian)。直(zhi)流或交流供(gong)電(dian)(dian)(dian)，具(ju)有4~20mADC，高(gao)低位開關量輸出(chu)(chu)。

天康超聲波液位計

工作原理如(ru)圖所示,超(chao)(chao)聲(sheng)波(bo)(bo)(bo)液(ye)位計一般采用收(shou)發(fa)合一的(de)(de)陶瓷(ci)超(chao)(chao)聲(sheng)波(bo)(bo)(bo)換能器(qi),聲(sheng)波(bo)(bo)(bo)的(de)(de)發(fa)射和接收(shou)都由(you)同一個探(tan)(tan)頭(tou)(tou)完成(cheng)。探(tan)(tan)頭(tou)(tou)向被測(ce)液(ye)面發(fa)射超(chao)(chao)聲(sheng)波(bo)(bo)(bo)信(xin)號,超(chao)(chao)聲(sheng)波(bo)(bo)(bo)由(you)探(tan)(tan)頭(tou)(tou)經(jing)傳播(bo)介質(zhi)傳播(bo)至被測(ce)液(ye)面,在液(ye)面上形成(cheng)反射,反射波(bo)(bo)(bo)沿原路徑傳播(bo)至探(tan)(tan)頭(tou)(tou),被探(tan)(tan)頭(tou)(tou)接收(shou)

原理要求
超聲波(bo)(bo)液位計工(gong)作時(shi)(shi)(shi)，高頻脈沖(chong)聲波(bo)(bo)由換能器（探(tan)頭(tou)）發出，遇被測物(wu)體（水(shui)面）表(biao)(biao)面被反射，折回的反射回波(bo)(bo)被同一換能器（探(tan)頭(tou)）接收，轉換成電信號。脈沖(chong)發送和接收之間(jian)(jian)的時(shi)(shi)(shi)間(jian)(jian)（聲波(bo)(bo)的運動時(shi)(shi)(shi)間(jian)(jian)）與(yu)換能器到物(wu)體表(biao)(biao)面的距離成正比，聲波(bo)(bo)傳(chuan)輸(shu)的距離S與(yu)聲速C和傳(chuan)輸(shu)時(shi)(shi)(shi)間(jian)(jian)T之間(jian)(jian)的關系可以用公式表(biao)(biao)示：S= CⅩT/2

安(an)裝超聲(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計時必(bi)(bi)須(xu)考(kao)慮超聲(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計的盲區問題。當液(ye)(ye)位(wei)(wei)(wei)進入(ru)盲區后，超聲(sheng)波(bo)(bo)變(bian)送(song)器就無法測量液(ye)(ye)位(wei)(wei)(wei)了，所以在(zai)確定超聲(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計的量程(cheng)時，必(bi)(bi)須(xu)留出50公(gong)分的余量，安(an)裝時，變(bian)送(song)器探頭(tou)必(bi)(bi)須(xu)高出液(ye)(ye)位(wei)(wei)(wei)50公(gong)分左右。這樣才能保(bao)證對液(ye)(ye)位(wei)(wei)(wei)的準確監測及保(bao)證超聲(sheng)波(bo)(bo)液(ye)(ye)位(wei)(wei)(wei)計的安(an)全。

在實際使用中(zhong)，因為安(an)裝時考慮不周，液位計(ji)被(bei)水(shui)淹沒，致(zhi)使液位計(ji)損壞。