Introduction to 3 ways to use a multimeter
Introduction to how to use a multimeter
A multimeter is a relatively practical and easy-to-learn testing tool. Multimeters are divided into analog and digital multimeters. Digital multimeters have quickly become popular due to their excellent performance and low price. In addition to the function of a pointer meter, a digital multimeter can also be used to measure capacitance, frequency, temperature, etc.
From the appearance, the upper part of the multimeter is the LCD screen, the middle part is the function selection knob, and the lower part is the test lead jack, which is divided into "com"-that is, the common end or the "-" end and the "+" end, and A current jack, a jack for measuring the beta value of the transistor and a jack for measuring the capacitance. Now let's talk about how to use it in detail.
Voltage measurement
1. Measurement of DC voltage, such as batteries, walkman power supplies, etc. First insert the black test lead into the "com" hole and the red test lead into the "V Ω" hole. Select the knob to a range larger than the estimated value (note: the values on the dial are the maximum range, "V-" represents the DC voltage range, "V~" represents the AC voltage range, and "A" represents the current range), and then Connect the test leads to both ends of the power supply or battery; keep the contact stable. The value can be read directly from the display. If it displays "1.", it means that the range is too small, so you need to increase the range before measuring. If "-" appears on the left side of the value, it means that the polarity of the test lead is opposite to the actual power supply polarity. At this time, the red test lead is connected to the negative pole.
2. Measurement of AC voltage. The test lead jack is the same as the DC voltage measurement, but the knob should be turned to the required range at the AC gear "V~". There is no positive or negative distinction between AC voltage, and the measurement method is the same as before. Regardless of whether you are measuring AC or DC voltage, you must pay attention to your personal safety and do not touch the metal parts of the test leads with your hands.
Measurement of current
1. Measurement of DC current
First insert the black test lead into the "COM" hole. If you measure a current greater than 200mA, insert the red test lead into the "10A" jack and turn the knob to the DC "10A" position; if you measure a current less than 200mA, insert the red test lead into the "200mA" jack and turn the knob. to a suitable range within DC 200mA. After adjustment, you can start measuring. Insert the multimeter into the circuit, keep it stable, and you can take a reading. If it displays "1.", then the range needs to be increased; if "-" appears on the left side of the value, it means that the current flows from the black test lead into the multimeter.
2. Measurement of AC current
The measurement method is basically the same as that of DC current, but the gear should be set to the AC gear. After the current measurement is completed, the red pen should be inserted back into the "VΩ" hole.
Measurement of resistance
Insert the test leads into the "COM" and "VΩ" holes, turn the knob to the required range in "Ω", and connect the test leads to the metal parts at both ends of the resistor. You can touch the resistor with your hands during measurement, but do not touch it with your hands at the same time. At both ends of the resistor, this will affect the measurement accuracy - the human body is a conductor with high resistance but limited resistance. When reading, keep the test lead and the resistor in good contact; pay attention to the unit: the unit is "Ω" in the "200" gear, the unit is "KΩ" in the "2K" to "200K" gear, and the unit above "2M" is "MΩ".
