How to measure resistance with multimeter and read resistance value
When repairing electronic circuit boards, the resistive components on the circuit board account for about 50% of the entire electronic components. If there is a fault in the circuit, the resistive component is one of the components we need to test.
So how to use a multimeter to measure resistance and read the resistance value? Let me tell you about this issue below. Before measuring resistance, we'd better perform two zero-adjustment operations. One is the mechanical zero-adjustment of the pointer multimeter; the second is the ohm zero-adjustment. After completing these two steps, you can select the appropriate resistance magnification file for resistance measurement. Since the scale of the multimeter's resistance range is uneven, when we select the magnification file, it is generally best to make the pointer scale stay in the sparse part of the scale. , and the closer the pointer is to the middle of the scale, the more accurate it will be. I recommend having the pointer point at 1/3 to 2/3 of the scale.
Reading method
The method of reading a multimeter is not complicated, that is, the reading on the meter head should be multiplied, which is the resistance value of the resistor being measured. For example, if you want to measure a resistor whose resistance is 47 ohms, then adjust the range to the "Rx10" ohm range. At this time, the pointer of the multimeter points to the position of 4.7, and the final reading is 4.7x10 which is 47 ohms. If you measure a large resistance, you can choose a larger resistance range, such as Rx1k or Rx10K. The method of reading the resistance value is the same.
Is the true effective value of a multimeter important?
What is True RMS?
Only true rms meters can accurately measure voltage/current. The calculation method of its average electric meter to measure AC signals is: the average value of the measured value × 1.11 = corrected to the effective value. True RMS The algorithm used by the electric meter to measure AC signals is: root mean square algorithm = true RMS. For pure sine waves, either true RMS or average value meters can accurately measure, but for non-sinusoidal waves such as square waves, triangle waves, and sawtooth waves, only true RMS meters can accurately measure. Nowadays, many electronic loads that have undergone frequency changes have non-sinusoidal waves. Only by having a true RMS multimeter can we accurately measure the correct value.
