一、電壓表可以用來干嘛

電(dian)壓表是用(yong)來測電(dian)壓的大(da)小的儀器(qi)，在電(dian)路中的符號(hao)為(wei)?。電(dian)壓表的電(dian)阻非常(chang)大(da)，可以當成開(kai)路。

使用電壓表時應注意以下幾點：

1、測電(dian)(dian)(dian)壓(ya)時(shi)，必須把電(dian)(dian)(dian)壓(ya)表并聯在(zai)被測電(dian)(dian)(dian)路的兩端。如果電(dian)(dian)(dian)壓(ya)表與被測用電(dian)(dian)(dian)器串(chuan)聯，則不(bu)能測出用電(dian)(dian)(dian)器兩端的電(dian)(dian)(dian)壓(ya)。

2、“+”“-”接(jie)線(xian)柱不(bu)能(neng)接(jie)反(fan)。如果電(dian)流從電(dian)壓表(biao)的(de)“-”接(jie)線(xian)柱流進，從“＋”接(jie)線(xian)柱流出(chu)，則指(zhi)針反(fan)轉，不(bu)能(neng)測出(chu)電(dian)壓，且容易損(sun)壞電(dian)壓表(biao)。

3、正確選擇(ze)量(liang)(liang)程(cheng)(cheng)(cheng)，被測(ce)(ce)(ce)(ce)電(dian)(dian)壓不要超過(guo)電(dian)(dian)壓表的(de)量(liang)(liang)程(cheng)(cheng)(cheng)，測(ce)(ce)(ce)(ce)量(liang)(liang)前先用(yong)(yong)電(dian)(dian)壓表的(de)大量(liang)(liang)程(cheng)(cheng)(cheng)，采用(yong)(yong)“試(shi)(shi)觸(chu)法”估計被測(ce)(ce)(ce)(ce)電(dian)(dian)壓的(de)大小(xiao)。試(shi)(shi)觸(chu)時，如(ru)果(guo)指(zhi)針偏轉角(jiao)(jiao)度(du)超過(guo)滿偏角(jiao)(jiao)度(du)，則(ze)被測(ce)(ce)(ce)(ce)電(dian)(dian)壓過(guo)大，無法測(ce)(ce)(ce)(ce)量(liang)(liang)且容(rong)易(yi)損壞電(dian)(dian)壓表。必須換(huan)(huan)用(yong)(yong)更大量(liang)(liang)程(cheng)(cheng)(cheng)的(de)電(dian)(dian)壓表進(jin)行測(ce)(ce)(ce)(ce)量(liang)(liang)。如(ru)果(guo)指(zhi)針正常偏轉，則(ze)用(yong)(yong)該量(liang)(liang)程(cheng)(cheng)(cheng)進(jin)行測(ce)(ce)(ce)(ce)量(liang)(liang)。如(ru)果(guo)指(zhi)針的(de)偏轉角(jiao)(jiao)度(du)非常小(xiao)，則(ze)應該換(huan)(huan)用(yong)(yong)較小(xiao)量(liang)(liang)程(cheng)(cheng)(cheng)進(jin)行測(ce)(ce)(ce)(ce)量(liang)(liang)。

二、電壓表可以直接接在電源兩極上嗎

前文已經簡單了解了電壓表是用來干嘛的，那么在使用電壓表測量電壓的時候，電壓表可以直接接在電源兩極上嗎？

電(dian)(dian)(dian)壓(ya)表可直接接在電(dian)(dian)(dian)源(yuan)兩極上，此(ci)時(shi)測(ce)出的電(dian)(dian)(dian)壓(ya)為電(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)壓(ya)。當(dang)然，量(liang)程(cheng)必須(xu)合適，如果電(dian)(dian)(dian)壓(ya)表量(liang)程(cheng)小于電(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)壓(ya)，則可能會(hui)燒壞電(dian)(dian)(dian)壓(ya)表。