Measuring Capacitance with a Digital Multimeter Benefits and Drawbacks
1, judge the polarity, the first multimeter to 100 or 1K ohm gear, assuming that a positive pole, so that the black pen and it connected to the red pen and another pole connected to write down the resistance, and then the capacitor discharge, that is, so that the two poles are in contact with each other, and then change the pen to measure the resistance, the resistance of a large time of the black pen connected to the positive pole of the capacitor.
2, the multimeter adjusted to the ohm gear appropriate gear, gear selection principle is: 1μF capacitance with 20K gear, 1-100μF capacitance with 2K gear, greater than 100,μF with 200 gear.
3, and then use the DT2201D multimeter red pen connected to the positive terminal of the capacitor, the black pen connected to the negative terminal of the capacitor, if the display slowly increases from 0, * after the display of the overflow symbols 1 is normal capacitance, if the display is always 0, the capacitance of the internal short-circuit, if the display is always 1, the capacitance of the internal circuit.
The use of the multimeter basic precautions
Multimeter is a relatively precise instrument, if not used properly, not only cause inaccurate measurement and very easy to damage. However, as long as we know how to use the multimeter and the precautions, and be careful, then the multimeter will last for a long time. The use of multimeter should pay attention to the following matters:
Measurement of current and voltage should not be rotated in the wrong gear. If the wrong resistance file or current file to measure the voltage, it is very easy to burn the meter. When the multimeter is not in use, it is best to rotate the gear to zero AC voltage to avoid damage due to improper use.
Measurement of DC voltage and DC current, pay attention to "+" "-" polarity, do not connect the wrong. If you find the pointer on the reversal, both should be immediately switched to the meter stick, so as not to damage the pointer and the meter head.
If you don't know the size of the measured voltage or current, you should use a large amount of range first, and then choose a suitable gear to test, so as to avoid excessive deflection of the needle and damage to the meter head. The closer the selected gear is to the measured value, the more accurate the measured value will be.
When measuring resistance, do not touch the bare ends of the components with your hands (or the metal parts of the two bars), so as to avoid parallel connection between the human body resistance and the measured resistance, which will make the measurement results inaccurate.
Measurement of resistance, such as the two sticks shorted, adjust the "zero ohm" knob to the maximum, the pointer is still not up to 0, this phenomenon is usually caused by insufficient voltage of the battery inside the table, should be replaced with new batteries to be able to measure accurately.
