How does a pointer multimeter measure resistance, and the process of measuring resistance with a multimeter
Pointer multimeter to measure resistance
The following is the process of measuring resistance with an analog multimeter:
1. First select the gear (there are ×1, ×10, ×100, ×1K, etc.), then directly contact the two test pens, and adjust the zero-setting resistance (the potentiometer can be rotated) so that the pointer points at the 0 ohm scale. (This step is called "resistance zeroing")
2. Then connect the two test leads to the two ends of the resistance to be measured (note that this resistance should not be connected to other circuits), then the resistance of the resistance is the number indicated * multiple. Example: Use ×100 gear, the pointer points to the 20 scale, the result is 20*100=2000 Euro.
Note: When the pointer is near the middle of the dial, the measured result is more accurate. (If the pointer is too close to both ends of the dial, you need to change the gear and re-zero the measurement)
1. If the resistance is measured online, the power supply and circuitous branch of the circuit under test should be cut off first. Make the branch where the resistor is located in an open circuit state.
2. First turn the switch to the resistance "Ω" range, and then select the appropriate resistance multiplier according to the approximate estimate.
3. The Ω block should be calibrated to zero before measurement. The method is: short-circuit the two test leads to see if the pointer points on the Ω zero scale; if it does not point to zero, turn the Ω zero adjustment button to calibrate until the pointer points to zero.
4. Connect the test leads to the two ends of the resistance under test respectively. At this time, the pointer will deflect. If the pointer does not stay within the range of 1/3 to 2/3 of the scale, the magnification block should be changed so that the pointer finally points within this range. (Because the pointer has higher measurement accuracy in this range). It should be noted that each time the magnification is changed, the Ω zero position must be re-calibrated before measurement can be performed.
5. Read the reading according to the position where the pointer stays: the measured resistance value = the reading indicated by the pointer × the number of magnifications.
