如(ru)何選(xuan)擇(ze)電(dian)(dian)子天(tian)(tian)(tian)平(ping)？選(xuan)擇(ze)電(dian)(dian)子天(tian)(tian)(tian)平(ping)應(ying)(ying)該從電(dian)(dian)子天(tian)(tian)(tian)平(ping)的(de)(de)(de)(de)(de)絕對(dui)(dui)精(jing)(jing)(jing)度（分度值e）上去考(kao)慮是(shi)(shi)否符(fu)合稱量的(de)(de)(de)(de)(de)精(jing)(jing)(jing)度要求。如(ru)選(xuan)0.1mg精(jing)(jing)(jing)度的(de)(de)(de)(de)(de)天(tian)(tian)(tian)平(ping)或0.01mg精(jing)(jing)(jing)度的(de)(de)(de)(de)(de)天(tian)(tian)(tian)平(ping)，切忌不(bu)(bu)可籠統地(di)說要萬(wan)分之一(yi)或十萬(wan)分之一(yi)精(jing)(jing)(jing)度的(de)(de)(de)(de)(de)天(tian)(tian)(tian)平(ping)，因(yin)為國外有些廠(chang)家是(shi)(shi)用(yong)相對(dui)(dui)精(jing)(jing)(jing)度來(lai)衡(heng)量天(tian)(tian)(tian)平(ping)的(de)(de)(de)(de)(de)，否則買來(lai)的(de)(de)(de)(de)(de)天(tian)(tian)(tian)平(ping)無法(fa)滿足用(yong)戶的(de)(de)(de)(de)(de)需要。例如(ru)在實(shi)際工(gong)作中遇到這(zhe)樣一(yi)個情況，用(yong)一(yi)臺(tai)實(shi)際標(biao)尺分度值d為1mg，檢定標(biao)尺分度值e為10mg，最(zui)大(da)(da)稱量為200g的(de)(de)(de)(de)(de)Mettler電(dian)(dian)子天(tian)(tian)(tian)平(ping)，用(yong)來(lai)稱量7mg的(de)(de)(de)(de)(de)物(wu)(wu)體(ti)，這(zhe)樣是(shi)(shi)不(bu)(bu)能得出(chu)準確結(jie)果的(de)(de)(de)(de)(de)：在《JJG98-90非自動天(tian)(tian)(tian)平(ping)試(shi)行檢定規程(cheng)》中規定，最(zui)大(da)(da)允許誤差(cha)與(yu)檢定標(biao)尺分度值“e"為同一(yi)數(shu)量級(ji)，此臺(tai)天(tian)(tian)(tian)平(ping)的(de)(de)(de)(de)(de)最(zui)大(da)(da)允許誤差(cha)為1e，顯然不(bu)(bu)能稱量7mg的(de)(de)(de)(de)(de)物(wu)(wu)體(ti)；稱量15mg的(de)(de)(de)(de)(de)物(wu)(wu)體(ti)用(yong)此類天(tian)(tian)(tian)平(ping)也(ye)不(bu)(bu)是(shi)(shi)*，因(yin)為其測試(shi)結(jie)果的(de)(de)(de)(de)(de)相對(dui)(dui)誤差(cha)會很(hen)大(da)(da)，應(ying)(ying)選(xuan)擇(ze)更高一(yi)級(ji)的(de)(de)(de)(de)(de)天(tian)(tian)(tian)平(ping)，有的(de)(de)(de)(de)(de)廠(chang)家在出(chu)廠(chang)時(shi)已(yi)規定了(le)最(zui)小稱量的(de)(de)(de)(de)(de)數(shu)值。因(yin)此我們在選(xuan)購及使用(yong)電(dian)(dian)子天(tian)(tian)(tian)平(ping)時(shi)必(bi)須(xu)考(kao)慮精(jing)(jing)(jing)度等級(ji)。⑵對(dui)(dui)稱量范圍的(de)(de)(de)(de)(de)要求：選(xuan)擇(ze)電(dian)(dian)子天(tian)(tian)(tian)平(ping)除(chu)了(le)看其精(jing)(jing)(jing)度，還應(ying)(ying)看最(zui)大(da)(da)稱量是(shi)(shi)否滿足量程(cheng)的(de)(de)(de)(de)(de)需要。通(tong)常(chang)取最(zui)大(da)(da)載荷加(jia)少許保險系數(shu)即可，也(ye)就(jiu)是(shi)(shi)常(chang)用(yong)載荷再放(fang)寬一(yi)些即可，不(bu)(bu)是(shi)(shi)越大(da)(da)越好。