How to measure and read resistance with a multimeter
In the repair of electronic circuit boards, circuit boards on its resistance components accounted for about 50% of the entire electronic components, if the circuit has a fault resistance components is one of the components we want to measure.
So how to use a multimeter to measure resistance and read the number of resistance? Below I give you the problems in this regard, before measuring resistance we had better carry out two zeroing operations, one is the pointer multimeter mechanical zeroing; the second is the ohm zeroing. After the operation of these two steps you can choose the appropriate resistance multiplier for resistance measurements, due to the multimeter resistance file scale is not uniform, we choose the multiplier file generally want to make the pointer scale stays in the sparse part of the scale is the best, and the closer the pointer is to the middle of the scale position the more accurate. I suggest that it is best to make the pointer in the scale of 1/3 to 2/3.
Reading Methods
The method of reading the multimeter is not complicated, that is, the reading of the meter head is multiplied by the multiplier, that is, the resistance value of the resistor to be measured. For example, to measure the resistance value of a resistor is 47 ohms, then the range to "Rx10" on the ohms file, then Hou multimeter pointer points to the position of 4.7, the final reading is 4.7x10 for 47 ohms. If the measurement of large resistors can choose a larger resistance range, such as Rx1k or Rx10K, they read the resistance value of the same method.
What are the phenomena and causes of ordinary pointer and digital multimeters?
With ordinary pointer multimeter directly in megohmmeter "L", "E" two ends of the measurement of its output rated DC voltage, the measurement results and the nominal rated voltage value is much smaller (out of the error range), and with a digital multimeter will not. The main reason is that the internal resistance of the pointer multimeter is small, while the digital multimeter internal resistance is relatively large. Pointer multimeter internal resistance is small, megohmmeter L-E output voltage is reduced a lot, not the output voltage of normal operation. It should be noted that, using the multimeter directly to measure the output voltage of megohmmeter is wrong, should be used with a larger internal resistance impedance of the electrostatic high voltage meter or a voltage divider and other load resistance is large enough to measure the way.
