倒标度欧姆表中,被测电阻与指示器、辅助电源串联。万用表的欧姆档即属于此类仪表。这种仪表刻度为非线性的,故其准确度等级以标度尺弧长的百分数表示,其误差也以弧长误差形式表示:式中,l′,l、L——分别为测得值弧长、标准值弧长和满度弧长。在欧姆表检定中,读取弧长既不方便又不准确。为此,采用读取电阻数值,再换算成弧长的方法。例如,以标准电阻R_x作实际值, Inverted scale ohmmeter, the measured resistance and indicator, auxiliary power in series. Ohm multimeter that is the type of instrument. This instrument scale is non-linear, so the level of accuracy to scale the percentage of arc length, said the error is also expressed in the form of arc length error: Where, l ’, l, L - were measured values Arc length, standard arc length and full arc length. In ohmmeter verification, reading arc length is neither convenient nor accurate. To this end, the use of reading the resistance value, and then converted into arc length of the method. For example, with the standard resistor R_x for the actual value,