Resistance is measured at the electrical barrier. Resistance values vary widely, from a few milliohms (mΩ) for contact resistance to billions of ohms for insulation resistance. Many DMMs measure resistances as small as 0.1 ohms, and some measurements can be as high as 300 megohms (300,000,000ohms). If the resistance is extremely large, the Fluke multimeter will display "OL", indicating that the measured resistance exceeds the range. When measuring an open circuit, "OL" is displayed.
La resistencia debe medirse con el circuito apagado, de lo contrario se producirán daños en el medidor o en la placa de circuito. Algunos multímetros digitales brindan una función de protección cuando una señal de voltaje se conecta por error en modo de resistencia. Los diferentes modelos de DMM tienen diferentes capacidades de protección.
For accurate measurements of low resistance, the resistance of the measuring lead must be subtracted from the measured value. Typical test lead resistance values are between {{0}}.2Ω and 0.5Ω. If the resistance of the test leads is greater than 1Ω, the test leads should be replaced.
Si el multímetro digital suministra menos de 0.6V CC de voltaje para medir la resistencia, puede medir el valor de resistencia de la placa de circuito aislado por el diodo o semiconductor. Se puede probar sin quitar la resistencia.
