表(biao)有用于(yu)計(ji)量檢(jian)定用電(dian)(dian)量應用狀(zhuang)況的無線水表(biao)，常統一安(an)裝在電(dian)(dian)表(biao)箱內或金屬材料表(biao)柜內，用于(yu)連(lian)續(xu)的計(ji)量檢(jian)定客戶的耗電(dian)(dian)量狀(zhuang)況。那(nei)麼，怎樣來挑(tiao)選電(dian)(dian)表(biao)也變成人們成套設備生產廠家關鍵事宜(yi)之一。依據很(hen)多年累積的工作經驗(yan)（experience)給(gei)大伙兒實際敘述一下電(dian)(dian)表(biao)的挑(tiao)選。

一、電表(biao)的性能參數(parameter)

如(ru)今銷售市場上普遍電(dian)(dian)(dian)(dian)表的性能(neng)(neng)參數為(wei)：額定(ding)(ding)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)220V，級別為(wei)2.0級、頻率(frequency)為(wei)50HZ。不一樣的主要(yao)參數是(shi)(shi)電(dian)(dian)(dian)(dian)表的校(xiao)準電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(Electron flow)和額定(ding)(ding)值較大電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)。校(xiao)準電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)就(jiu)是(shi)(shi)指電(dian)(dian)(dian)(dian)表長期(qi)性一切正常運作的基(ji)(ji)礎電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)，是(shi)(shi)明(ming)確電(dian)(dian)(dian)(dian)表相關(guan)特(te)點的電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)值，以Ib表達(da)。額定(ding)(ding)值較大電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)就(jiu)是(shi)(shi)指電(dian)(dian)(dian)(dian)表能(neng)(neng)考慮其(qi)生產制(zhi)造標準的度的較大電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)值，以Imax表達(da)。如(ru)Imax低于(yu)基(ji)(ji)礎電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)的1時，只標出(chu)基(ji)(ji)礎電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)。因而，采用(yong)哪些的電(dian)(dian)(dian)(dian)表一定(ding)(ding)要(yao)依(yi)據負(fu)載電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)的尺寸來明(ming)確。用(yong)電(dian)(dian)(dian)(dian)負(fu)荷的限(xian)制(zhi)應不超出(chu)電(dian)(dian)(dian)(dian)表的短路容量，低限(xian)不可小于(yu)電(dian)(dian)(dian)(dian)表容許(xu)偏差要(yao)求的負(fu)載電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)值。

此外，家中常(chang)見的(de)負(fu)載(zai)電流(Electron flow)是(shi)高于10%的(de)校(xiao)準電流值(zhi)，那(nei)樣(yang)即能確保電表的(de)計量檢定性，又能確保電表自(zi)身的(de)安全(quan)性。

二、電表不應有潛動狀況

潛(qian)動就(jiu)是指當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)表(biao)(biao)(biao)再加(jia)額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)，但負(fu)載(zai)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(Electron flow)為零時，電(dian)(dian)(dian)(dian)(dian)(dian)表(biao)(biao)(biao)的(de)(de)(de)輪盤(pan)不斷(duan)的(de)(de)(de)持續（Continuity)旋(xuan)(xuan)轉(zhuan)。因而，當(dang)你要想評定(ding)(近義詞(ci):判斷(duan)、分辨、裁定(ding))一(yi)塊電(dian)(dian)(dian)(dian)(dian)(dian)表(biao)(biao)(biao)是不是有潛(qian)動狀況(kuang)，將220V的(de)(de)(de)交流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)加(jia)進電(dian)(dian)(dian)(dian)(dian)(dian)表(biao)(biao)(biao)的(de)(de)(de)工作(zuo)電(dian)(dian)(dian)(dian)(dian)(dian)壓磁圈(quan)(winding)兩邊（即電(dian)(dian)(dian)(dian)(dian)(dian)能(neng)表(biao)(biao)(biao)接線端鈕的(de)(de)(de)1端和3端或5端），這時電(dian)(dian)(dian)(dian)(dian)(dian)表(biao)(biao)(biao)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)磁圈(quan)因為無負(fu)載(zai)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)存有，所欲電(dian)(dian)(dian)(dian)(dian)(dian)表(biao)(biao)(biao)的(de)(de)(de)輪盤(pan)應終止旋(xuan)(xuan)轉(zhuan)或數多旋(xuan)(xuan)轉(zhuan)不超出(chu)一(yi)一(yi)圈(quan)定(ding)位(wei)及格，不然(ran)為不過關。

三、電表的外型巡視(shi)

1.電表接(jie)線端鈕的表蓋(gai)上(shang)應有顯著的接(jie)線電路(lu)原理圖。

2.電(dian)表(biao)出(chu)廠銘牌(pai)上的筆(bi)跡（包(bao)含(han)計度(du)器上的筆(bi)跡）要清楚(chu)，標識要詳細，表(biao)帶無毀壞(huai)，密封性好(hao)些。

3.電表應有供計讀轉速(su)的(de)色標或色標部位（position )（當防潛動針距(ju)防潛鉤終(zhong)時，色標應在正前）。

4.電表(biao)的(de)輪盤在旋轉時應無蹭盤狀(zhuang)況，另外表(biao)帶應有鉛(外型(xing):帶天(tian)藍色(se)的(de)銀色(se))封。

5.為保證電(dian)表的(de)品質，是采(cai)用經營規(gui)模(mo)很大的(de)生產制造(Produce)生產廠家，選購后一(yi)定(ding)要送至本地有段(duan)計(ji)量檢(jian)(jian)定(ding)單位校檢(jian)(jian)及格后，方可應(ying)用。

四、電表的安裝與應用(yong)

電表(biao)需(xu)裝在(zai)(zai)易(yi)抄讀表(biao)，光源(yuan)充(chong)裕，干躁且不(bu)會受到震(zhen)動(dong)的(de)(de)地(di)區(qu)，是(shi)距路面未17-2m的(de)(de)地(di)方(fang)，應該和別的(de)(de)用電量(liang)機器設(she)備有一(yi)定的(de)(de)間距，禁止在(zai)(zai)有浸蝕(shi)(shi)(釋(shi)意:指腐(fu)化、消退、腐(fu)蝕(shi)(shi)等(deng))氣(qi)體的(de)(de)地(di)區(qu)安裝電表(biao)。另外，電表(biao)不(bu)必安裝在(zai)(zai)密封性的(de)(de)小箱子里，那樣電表(biao)不(bu)容易(yi)熱管(guan)散熱，易(yi)絕緣層(insulated)脆化。

電表(biao)耐受性自然環(huan)境標(biao)(biao)準的(de)(de)(de)工作能力一般分(fen)成P（或不標(biao)(biao)識）、S、A、B四組。她們的(de)(de)(de)參(can)比溫度(du)（temperature)均(jun)為(wei) 23℃，參(can)比環(huan)境濕(shi)度(du)均(jun)為(wei)40-60%。P、S的(de)(de)(de)溫度(du)規定值均(jun)為(wei)-25~ 40℃環(huan)境濕(shi)度(du)均(jun)為(wei)25%~80%。A、B的(de)(de)(de)溫度(du)規定值各自為(wei)0~ 40℃和-20~ 50℃，環(huan)境濕(shi)度(du)均(jun)為(wei)25~80%。實際安裝哪些(xie)的(de)(de)(de)電表(biao)要依據本地的(de)(de)(de)實際上自然環(huan)境標(biao)(biao)準定。

電(dian)(dian)(dian)(dian)表一(yi)定(ding)要(yao)依(yi)照路(lu)線(xian)(xian)(xian)圖恰(qia)當的(de)(de)(de)連接(jie)(jie)電(dian)(dian)(dian)(dian)力網(wang)，電(dian)(dian)(dian)(dian)表的(de)(de)(de)電(dian)(dian)(dian)(dian)流(Electron flow)磁圈(quan)(winding)應串接(jie)(jie)在開(kai)關電(dian)(dian)(dian)(dian)源(yuan)的(de)(de)(de)相線(xian)(xian)(xian)（別名火線(xian)(xian)(xian)零線(xian)(xian)(xian)），工(gong)作電(dian)(dian)(dian)(dian)壓磁圈(quan)則跨收到(dao)開(kai)關電(dian)(dian)(dian)(dian)源(yuan)的(de)(de)(de)相線(xian)(xian)(xian)和(he)零線(xian)(xian)(xian)中間。避免因為不(bu)正(zheng)確接(jie)(jie)線(xian)(xian)(xian)導致電(dian)(dian)(dian)(dian)表損壞或(huo)不(bu)正(zheng)確計量(liang)檢定(ding)。一(yi)旦(dan)產(chan)生(sheng)常見(jian)故障一(yi)定(ding)要(yao)請(qing)技(ji)術人(ren)員檢修和(he)校驗，不(bu)可以隨意開(kai)啟鉛(外(wai)型:帶天藍色的(de)(de)(de)銀色)封，私自修改路(lu)線(xian)(xian)(xian)及拆(chai)換元器件。

應用電(dian)(dian)表時，一(yi)定要將電(dian)(dian)表接(jie)(jie)線端子(zi)的螺釘（screw)扭緊，使輸電(dian)(dian)線與接(jie)(jie)線端子(zi)排密不(bu)可分觸碰，避免因為松脫導致點火或觸碰不(bu)太好，使電(dian)(dian)表的接(jie)(jie)線端子(zi)燒毀(hui)，使電(dian)(dian)表轉停，撥通量遺失(shi)。