優(you)儀高(gao)測電(dian)(dian)(dian)筆是(shi)(shi)寬廣電(dian)(dian)(dian)工常常運用(yong)的(de)(de)東西之一(yi)，用(yong)來(lai)差異物體(ti)是(shi)(shi)不是(shi)(shi)帶電(dian)(dian)(dian)。它的(de)(de)內(nei)部構造是(shi)(shi)一(yi)只(zhi)需兩個電(dian)(dian)(dian)極的(de)(de)燈泡(pao)，泡(pao)內(nei)充有(you)氖氣(qi)，俗稱氖泡(pao)，它的(de)(de)一(yi)極接到(dao)筆尖，另一(yi)極串(chuan)聯一(yi)只(zhi)高(gao)電(dian)(dian)(dian)阻后(hou)接到(dao)筆的(de)(de)另一(yi)端。當(dang)氖泡(pao)的(de)(de)南北(bei)(bei)極間電(dian)(dian)(dian)壓(ya)抵達必定值時，南北(bei)(bei)極間便發作輝(hui)光，輝(hui)光強弱與南北(bei)(bei)極間電(dian)(dian)(dian)壓(ya)成正比(bi)。