條式水平儀是(shi)鉗工常用的(de)(de)水(shui)平(ping)(ping)(ping)(ping)儀(yi)，條式水(shui)平(ping)(ping)(ping)(ping)儀(yi)由(you)作(zuo)為工作(zuo)平(ping)(ping)(ping)(ping)面的(de)(de)V型底平(ping)(ping)(ping)(ping)面和與工作(zuo)平(ping)(ping)(ping)(ping)面平(ping)(ping)(ping)(ping)行的(de)(de)水(shui)準器(qi)與工作(zuo)平(ping)(ping)(ping)(ping)面的(de)(de)平(ping)(ping)(ping)(ping)行度都做得很   。當水(shui)平(ping)(ping)(ping)(ping)儀(yi)的(de)(de)底平(ping)(ping)(ping)(ping)面放在準確(que)的(de)(de)水(shui)平(ping)(ping)(ping)(ping)位置(zhi)(zhi)時，水(shui)準器(qi)內的(de)(de)氣泡正好(hao)在中間位置(zhi)(zhi)（即水(shui)平(ping)(ping)(ping)(ping)位置(zhi)(zhi)）。

條(tiao)式(shi)(shi)水(shui)(shui)(shui)(shui)平(ping)(ping)(ping)(ping)儀(yi)(yi)是鉗(qian)工(gong)常用的(de)(de)(de)水(shui)(shui)(shui)(shui)平(ping)(ping)(ping)(ping)儀(yi)(yi)，條(tiao)式(shi)(shi)水(shui)(shui)(shui)(shui)平(ping)(ping)(ping)(ping)儀(yi)(yi)由(you)作(zuo)為工(gong)作(zuo)平(ping)(ping)(ping)(ping)面的(de)(de)(de)V型底平(ping)(ping)(ping)(ping)面和與(yu)工(gong)作(zuo)平(ping)(ping)(ping)(ping)面平(ping)(ping)(ping)(ping)行(xing)的(de)(de)(de)水(shui)(shui)(shui)(shui)準(zhun)(zhun)器與(yu)工(gong)作(zuo)平(ping)(ping)(ping)(ping)面的(de)(de)(de)平(ping)(ping)(ping)(ping)行(xing)度都做(zuo)得很(hen)   。當(dang)水(shui)(shui)(shui)(shui)平(ping)(ping)(ping)(ping)儀(yi)(yi)的(de)(de)(de)底平(ping)(ping)(ping)(ping)面放在準(zhun)(zhun)確的(de)(de)(de)水(shui)(shui)(shui)(shui)平(ping)(ping)(ping)(ping)位置(zhi)時(shi)，水(shui)(shui)(shui)(shui)準(zhun)(zhun)器內的(de)(de)(de)氣(qi)泡(pao)(pao)正好在中間位置(zhi)（即水(shui)(shui)(shui)(shui)平(ping)(ping)(ping)(ping)位置(zhi)）。在水(shui)(shui)(shui)(shui)準(zhun)(zhun)器玻璃(li)管(guan)內氣(qi)泡(pao)(pao)兩(liang)(liang)端(duan)(duan)刻線為零(ling)線的(de)(de)(de)兩(liang)(liang)邊，刻有(you)不(bu)(bu)少8格的(de)(de)(de)刻度，刻線間距為2mm，當(dang)水(shui)(shui)(shui)(shui)平(ping)(ping)(ping)(ping)儀(yi)(yi)的(de)(de)(de)底面與(yu)水(shui)(shui)(shui)(shui)平(ping)(ping)(ping)(ping)位置(zhi)有(you)微(wei)小的(de)(de)(de)差別時(shi)，也(ye)就(jiu)(jiu)是水(shui)(shui)(shui)(shui)平(ping)(ping)(ping)(ping)儀(yi)(yi)底平(ping)(ping)(ping)(ping)面的(de)(de)(de)兩(liang)(liang)端(duan)(duan)有(you)高(gao)(gao)低(di)時(shi)，水(shui)(shui)(shui)(shui)準(zhun)(zhun)器內氣(qi)泡(pao)(pao)由(you)于地(di)心引力的(de)(de)(de)作(zuo)用總是往水(shui)(shui)(shui)(shui)準(zhun)(zhun)器的(de)(de)(de)   高(gao)(gao)一側移(yi)動(dong)(dong)，這就(jiu)(jiu)是水(shui)(shui)(shui)(shui)平(ping)(ping)(ping)(ping)儀(yi)(yi)的(de)(de)(de)使用原理。兩(liang)(liang)端(duan)(duan)高(gao)(gao)低(di)相差不(bu)(bu)多時(shi)，氣(qi)泡(pao)(pao)移(yi)動(dong)(dong)也(ye)不(bu)(bu)多，兩(liang)(liang)端(duan)(duan)高(gao)(gao)低(di)相差較(jiao)大時(shi)，氣(qi)泡(pao)(pao)移(yi)動(dong)(dong)也(ye)較(jiao)大，在水(shui)(shui)(shui)(shui)準(zhun)(zhun)器的(de)(de)(de)刻度上就(jiu)(jiu)可讀出兩(liang)(liang)端(duan)(duan)高(gao)(gao)低(di)的(de)(de)(de)差值。

條(tiao)式(shi)水(shui)(shui)平(ping)儀(yi)的(de)(de)規格(ge)(ge)是見表1，條(tiao)式(shi)水(shui)(shui)平(ping)儀(yi)分度(du)(du)(du)值的(de)(de)說(shuo)明(ming)，如分度(du)(du)(du)值0.03mm/m即(ji)表示氣(qi)泡(pao)稱動一格(ge)(ge)時(shi)(shi)，被(bei)測量長(chang)度(du)(du)(du)為(wei)(wei)1m的(de)(de)兩端(duan)(duan)上(shang)，高(gao)(gao)度(du)(du)(du)相(xiang)差0.03mm，再如用200mm長(chang)，分度(du)(du)(du)值為(wei)(wei)0.05mm/m的(de)(de)水(shui)(shui)平(ping)儀(yi)，測量400mm長(chang)的(de)(de)平(ping)面的(de)(de)水(shui)(shui)平(ping)度(du)(du)(du)，先把水(shui)(shui)平(ping)儀(yi)放(fang)在(zai)(zai)平(ping)面的(de)(de)左(zuo)側，此(ci)(ci)時(shi)(shi)若氣(qi)泡(pao)向右(you)(you)移(yi)動兩格(ge)(ge)，再水(shui)(shui)平(ping)儀(yi)放(fang)在(zai)(zai)平(ping)面的(de)(de)右(you)(you)側，此(ci)(ci)時(shi)(shi)若氣(qi)泡(pao)向左(zuo)移(yi)動三格(ge)(ge)，則說(shuo)明(ming)這個平(ping)面是中(zhong)(zhong)(zhong)間(jian)(jian)(jian)高(gao)(gao)兩側低(di)的(de)(de)凸平(ping)面。中(zhong)(zhong)(zhong)間(jian)(jian)(jian)高(gao)(gao)出(chu)(chu)(chu)多少(shao)毫米呢？從(cong)(cong)左(zuo)側看中(zhong)(zhong)(zhong)間(jian)(jian)(jian)比(bi)左(zuo)側高(gao)(gao)出(chu)(chu)(chu)二格(ge)(ge)，即(ji)在(zai)(zai)被(bei)測量長(chang)度(du)(du)(du)為(wei)(wei)1m米時(shi)(shi)，中(zhong)(zhong)(zhong)間(jian)(jian)(jian)高(gao)(gao)2×0.05=0.10mm，現(xian)實(shi)際測量長(chang)度(du)(du)(du)為(wei)(wei)200mm，是1m的(de)(de)1/5，所以(yi)，實(shi)際上(shang)中(zhong)(zhong)(zhong)間(jian)(jian)(jian)比(bi)左(zuo)端(duan)(duan)高(gao)(gao)0.10×2=0.02mm，從(cong)(cong)右(you)(you)側看：中(zhong)(zhong)(zhong)間(jian)(jian)(jian)比(bi)右(you)(you)端(duan)(duan)高(gao)(gao)三格(ge)(ge)，即(ji)在(zai)(zai)被(bei)測量長(chang)度(du)(du)(du)為(wei)(wei)1m時(shi)(shi)，中(zhong)(zhong)(zhong)間(jian)(jian)(jian)高(gao)(gao)3×0.05=0.15mm，現(xian)實(shi)際測長(chang)度(du)(du)(du)為(wei)(wei)200mm，是1m的(de)(de)1/5，所以(yi)實(shi)際上(shang)中(zhong)(zhong)(zhong)間(jian)(jian)(jian)比(bi)右(you)(you)端(duan)(duan)高(gao)(gao)0.15×1/5=0.03mm，由此(ci)(ci)可知，中(zhong)(zhong)(zhong)間(jian)(jian)(jian)比(bi)左(zuo)端(duan)(duan)高(gao)(gao)0.02mm，中(zhong)(zhong)(zhong)間(jian)(jian)(jian)比(bi)右(you)(you)端(duan)(duan)高(gao)(gao)0.03mm，則中(zhong)(zhong)(zhong)間(jian)(jian)(jian)比(bi)兩端(duan)(duan)高(gao)(gao)出(chu)(chu)(chu)的(de)(de)數值為(wei)(wei)（0.02÷0.03）÷2÷0.025mm。