The Three Key Steps for Measuring Resistance with a Multimeter
1. The multimeter we use has a common meter head for measuring voltage, current, and resistance. When measuring resistance, we first need to set it to the ohm range. Generally, there are several gears: X1, X10, X100, and X1000.
2. If the pointer of the meter or (when the second arm of the digital multimeter is short circuited, the reading is not zero) before measurement, it will cause zero error in the reading. If we find that it has not been reset to zero before testing, we must first adjust it to zero position. The method is as follows:
3. Select magnification
Using a multimeter to measure resistance with a resistance meter, in order to facilitate accurate readings, it is necessary to place the pointer as close as possible to the middle of the dial, so it is necessary to select the appropriate magnification gear. If the multimeter does not have a 10k
multiplier gear, the closest gear can be selected.
Connect the V terminal of the multimeter to one end of the resistor and the V terminal to the other end of the resistor, and then set the multimeter to measure. A multimeter provides a source current to a resistor and calculates the voltage across the resistor, which can be determined by Ohm's law.
Based on the simplified example above, the lead resistance R can cause significant issues because the voltage is the same as the voltage of the three resistors mentioned above. This effect is greater in the case of low resistance, and is generally evident at 30K Ω. Of course, these are all aimed at high-precision situations. If the accuracy requirements are not high, this method can be used.
The effect caused by wire resistance R can be eliminated through some relative value measurement functions of a multimeter. To eliminate these problems, the first thing to determine is where they come from. This can be achieved by setting the resistance to 0 Ω.
If all resistors are placed at both ends of the test lead, they can be measured using two wires for relative value measurement.
