辨(bian)別(bie)壓(ya)力(li)變(bian)送(song)器(qi)的(di)真(zhen)假(jia)優(you)劣(lie)有(you)以(yi)下(xia)幾(ji)點(dian):
1、基(ji)準(zhun)要(yao)穩(wen),4mA是(shi)對(dui)應(ying)的(di)輸(shu)入(ru)零(ling)位(wei)基(ji)準(zhun),基(ji)準(zhun)不(bu)穩(wen),談(tan)何(he)精(jing)度(duo)線(xian)性(xing)度(duo),冷(leng)開(kai)機(ji)3分(fen)鍾(zhong)內(nei)4mA的(di)零(ling)位(wei)漂(piao)移(yi)變(bian)化(hua)不(bu)超(chao)過(guo)4.000mA0.5%以(yi)內(nei);(即(ji)3.98-4.02mA),負(fu)載(zai)250Ω上(shang)的(di)壓(ya)降(xiang)為(wei)0.995-1.005V,國(guo)外(wai)IC芯(xin)片(pian)多(duo)用(yong)昂(ang)貴(gui)的(di)能(neng)隙(xi)基(ji)準(zhun),溫(wen)漂(piao)係(ji)數(shuo)每(mei)度(duo)變(bian)化(hua)10ppm;
2、內(nei)電(dian)路(lu)總(zong)計(ji)消(xiao)耗(hao)電(dian)流(liu)<4mA,加(jia)整(zheng)定(ding)後(hou)等(deng)於(yu)4.000mA,而(er)且(qie)有(you)源(yuan)整(zheng)流(liu)濾(lv)波(bo)放(fang)大(dai)恒(heng)流(liu)電(dian)路(lu)不(bu)因(yin)原(yuan)邊(bian)輸(shu)入(ru)變(bian)化(hua)而(er)消(xiao)耗(hao)電(dian)流(liu)也(ye)隨(sui)之(zhi)變(bian)化(hua),國(guo)外(wai)IC芯(xin)片(pian)采(cai)用(yong)恒(heng)流(liu)供(gong)電(dian);
3、當(dang)工(gong)作(zuo)電(dian)壓(ya)24.000V時(shi),滿(man)量(liang)程(cheng)20.000mA時(shi),滿(man)量(liang)程(cheng)20.000mA的(di)讀(dou)數(shuo)不(bu)會(kuai)因(yin)負(fu)載(zai)0-700Ω變(bian)化(hua)而(er)變(bian)化(hua);變(bian)化(hua)不(bu)超(chao)過(guo)20.000mA0.5%以(yi)內(nei);
4、當(dang)滿(man)量(liang)程(cheng)20.000mA時(shi),負(fu)載(zai)250Ω時(shi),滿(man)量(liang)程(cheng)20.000mA的(di)讀(dou)數(shuo)不(bu)會(kuai)因(yin)工(gong)作(zuo)電(dian)壓(ya)15.000V-30.000V變(bian)化(hua)而(er)變(bian)化(hua);變(bian)化(hua)不(bu)超(chao)過(guo)20.000mA0.5%以(yi)內(nei);
5、當(dang)原(yuan)邊(bian)過(guo)載(zai)時(shi),輸(shu)出(chu)電(dian)流(liu)不(bu)超(chao)過(guo)25.000mA+10%以(yi)內(nei),否(pi)則(ze)PLC/DCS內(nei)供(gong)變(bian)送(song)器(qi)用(yong)的(di)24V工(gong)作(zuo)電(dian)源(yuan)和(hu)A/D輸(shu)入(ru)箝(qian)位(wei)電(dian)路(lu)因(yin)功(gong)耗(hao)過(guo)大(dai)而(er)損(sun)壞(huai),另(ling)外(wai)變(bian)送(song)器(qi)內(nei)的(di)射(she)隨(sui)輸(shu)出(chu)亦(yi)因(yin)功(gong)耗(hao)過(guo)大(dai)而(er)損(sun)壞(huai),無(wu)A/D輸(shu)入(ru)箝(qian)位(wei)電(dian)路(lu)的(di)更(geng)遭(zao)殃(yang);
6、當(dang)工(gong)作(zuo)電(dian)壓(ya)24V接(jie)反(fan)時(shi)不(bu)得(dei)損(sun)壞(huai)變(bian)送(song)器(qi),必(bi)須(xu)有(you)性(xing)保(bao)護(hu);
7、當(dang)兩(liang)線(xian)之(zhi)間(jian)因(yin)感(gan)應(ying)雷(lei)及(ji)感(gan)應(ying)浪(lang)湧(chong)電(dian)壓(ya)超(chao)過(guo)24V時(shi)要(yao)箝(qian)位(wei),不(bu)得(dei)損(sun)壞(huai)變(bian)送(song)器(qi);一(yi)般(pan)在(zai)兩(liang)線(xian)之(zhi)間(jian)並(bing)聯(lian)1-2隻(zhi)TVS瞬(shun)態(tai)保(bao)護(hu)二(er)管(guan)1.5KE可(ke)抑(yi)製(zhi)每(mei)20秒(miao)間(jian)隔(ge)一(yi)次(ci)的(di)20毫(hao)秒(miao)脈(mo)寬(kuan)的(di)正(zheng)反(fan)脈(mo)衝(chong)的(di)衝(chong)擊(ji),瞬(shun)態(tai)承(cheng)受(shou)衝(chong)擊(ji)功(gong)率(shuai)1.5KW-3KW;
8、產(chan)品(pin)標(biao)示(shi)的(di)線(xian)性(xing)度(duo)0.5%是(shi)誤(wu)差(chai)還(huan)是(shi)相(xiang)對(dui)誤(wu)差(chai),可(ke)以(yi)按(an)以(yi)下(xia)方(fang)法(fa)來(lai)辨(bian)別(bie)方(fang)可(ke)一(yi)目(mu)了(liao)然(ran):符(fu)合(ge)下(xia)述(shu)指(zhi)標(biao)是(shi)真(zhen)的(di)線(xian)性(xing)度(duo)0.5%;原(yuan)邊(bian)輸(shu)入(ru)為(wei)零(ling)時(shi)輸(shu)出(chu)4mA正(zheng)負(fu)0.5%(3.98-4.02mA),負(fu)載(zai)250Ω上(shang)的(di)壓(ya)降(xiang)為(wei)0.995-1.005V;原(yuan)邊(bian)輸(shu)入(ru)10%時(shi)輸(shu)出(chu)5.6mA正(zheng)負(fu)0.5%(5.572-5.628mA)負(fu)載(zai)250歐(ou)姆(mu)上(shang)的(di)壓(ya)降(xiang)為(wei)1.393-1.407V;原(yuan)邊(bian)輸(shu)入(ru)25%時(shi)輸(shu)出(chu)8mA正(zheng)負(fu)0.5%(7.96-8.04mA)負(fu)載(zai)250Ω上(shang)的(di)壓(ya)降(xiang)為(wei)1.990-2.010V;原(yuan)邊(bian)輸(shu)入(ru)50%時(shi)輸(shu)出(chu)12mA正(zheng)負(fu)0.5%(11.94-12.06mA)負(fu)載(zai)250Ω上(shang)的(di)壓(ya)降(xiang)為(wei)2.985-3.015V;原(yuan)邊(bian)輸(shu)入(ru)75%時(shi)輸(shu)出(chu)16mA正(zheng)負(fu)0.5%(15.92-16.08mA)負(fu)載(zai)250Ω上(shang)的(di)壓(ya)降(xiang)為(wei)3.980-4.020V;原(yuan)邊(bian)輸(shu)時(shi)輸(shu)出(chu)20mA正(zheng)負(fu)0.5%(19.90-20.10mA)負(fu)載(zai)250Ω上(shang)的(di)壓(ya)降(xiang)為(wei)4.975-5.025V。
9、原(yuan)邊(bian)輸(shu)入(ru)過(guo)載(zai)時(shi)必(bi)須(xu)限(xian)流(liu):原(yuan)邊(bian)輸(shu)入(ru)過(guo)載(zai)大(dai)於(yu)125%時(shi)輸(shu)出(chu)過(guo)流(liu)限(xian)製(zhi)25mA+10%(25.00-27.50mA)負(fu)載(zai)250Ω上(shang)的(di)壓(ya)降(xiang)為(wei)6.250-6.875V;
10、感(gan)應(ying)浪(lang)湧(chong)電(dian)壓(ya)超(chao)過(guo)24V時(shi)有(you)無(wu)箝(qian)位(wei)的(di)辨(bian)別(bie):在(zai)兩(liang)線(xian)輸(shu)出(chu)端(duan)口(kou)並(bing)一(yi)個(ge)交(jiao)流(liu)50V指(zhi)針(zhen)式(shi)表(biao)頭(tou),用(yong)交(jiao)流(liu)50V接(jie)兩(liang)根(gen)線(xian)去(qu)瞬(shun)間(jian)碰(peng)一(yi)下(xia)兩(liang)線(xian)輸(shu)出(chu)端(duan)口(kou),看(kan)有(you)無(wu)箝(qian)位(wei),箝(qian)位(wei)多(duo)少(shao)伏(fu)可(ke)一(yi)目(mu)了(liao)然(ran)啦(la);
11、有(you)無(wu)性(xing)保(bao)護(hu)的(di)辨(bian)別(bie):用(yong)指(zhi)針(zhen)式(shi)萬(mo)用(yong)表(biao)Ω乘(sheng)10K檔(dang)正(zheng)反(fan)測(ce)量(liang)兩(liang)線(xian)輸(shu)出(chu)端(duan)口(kou),總(zong)有(you)一(yi)次(ci)Ω阻(zu)值(zhi)大(dai),就(jiu)有(you)性(xing)保(bao)護(hu);
12、有(you)無(wu)輸(shu)出(chu)電(dian)流(liu)長(zhang)時(shi)間(jian)短(duan)路(lu)保(bao)護(hu):原(yuan)邊(bian)輸(shu)入(ru)時(shi)或(huo)過(guo)載(zai)大(dai)於(yu)125%-200%時(shi),將(qiang)負(fu)載(zai)250Ω短(duan)路(lu),測(ce)量(liang)短(duan)路(lu)保(bao)護(hu)限(xian)製(zhi)是(shi)否(pi)在(zai)25mA+10%;
13、工(gong)業(ye)級(ji)別(bie)和(hu)民(min)用(yong)商(shang)用(yong)級(ji)別(bie)的(di)辨(bian)別(bie):工(gong)業(ye)級(ji)別(bie)工(gong)作(zuo)溫(wen)度(duo)範(fan)圍(wei)是(shi)-25度(duo)到(dao)+70度(duo),溫(wen)漂(piao)係(ji)數(shuo)是(shi)每(mei)度(duo)變(bian)化(hua)100ppm,即(ji)溫(wen)度(duo)每(mei)度(duo)變(bian)化(hua)1度(duo),精(jing)度(duo)變(bian)化(hua)為(wei)萬(mo)分(fen)之(zhi)一(yi);民(min)用(yong)商(shang)用(yong)級(ji)別(bie)工(gong)作(zuo)溫(wen)度(duo)範(fan)圍(wei)是(shi)0度(duo)(或(huo)-10度(duo))到(dao)+70度(duo)(或(huo)+50度(duo)),溫(wen)漂(piao)係(ji)數(shuo)是(shi)每(mei)度(duo)變(bian)化(hua)250ppm,即(ji)溫(wen)度(duo)每(mei)度(duo)變(bian)化(hua)1度(duo),精(jing)度(duo)變(bian)化(hua)為(wei)萬(mo)分(fen)之(zhi)二(er)點(dian)五(wu);電(dian)流(liu)電(dian)壓(ya)變(bian)送(song)器(qi)的(di)溫(wen)漂(piao)係(ji)數(shuo)可(ke)以(yi)用(yong)恒(heng)溫(wen)箱(xiang)或(huo)高(gao)低(di)溫(wen)箱(xiang)來(lai)試(shi)驗(yan)驗(yan)證(zheng)較(jiao)繁(fan)瑣(suo)。




