Tips for Using a Multimeter in Electronic System Testing and Measurement
Multimeter "is the abbreviation for a multimeter, which is an essential tool in our electronic production. The advantages of a multimeter are its versatility, wide range, and ease of use. A multimeter can measure current, voltage, resistance, and some can also measure the amplification factor of a transistor, frequency, capacitance value, logic potential, decibel value, etc. There are many types of multimeters, and the most popular ones now are mechanical pointer and digital multimeters. They each have their own advantages. Mastering the usage of a multimeter is a fundamental skill in electronic technology. A small multimeter has many technical principles and usage techniques. If you don't believe it, take a look at our half month topic!
Multimeters are divided into pointer type and digital type, each with its own convenience. It is difficult to say who is good or bad, and it is best to have one pointer and one digital type. A pointer type MF30 multimeter is sufficient for amateur electronic production, which is a classic model. There is also the veteran MF500 multimeter and the cheap MF50 multimeter, which can generally be purchased at telecom stores.
The three basic functions of a multimeter are to measure resistance, voltage, and current, so the predecessors called it a multimeter.
Nowadays, multimeters have added many new functions, especially digital multimeters, such as measuring capacitance value, transistor amplification factor, diode voltage drop, etc. There is also a talking digital multimeter that can broadcast measurement results in language.
The biggest feature of a multimeter is that it has a range conversion switch, which is used to switch various functions. Basically, A - is used to represent measuring DC current, with milliampere and ampere levels generally divided into several levels. V - stands for measuring DC voltage. High end multimeters have millivolt range and voltage range. V~is used to measure AC voltage. Measure AC current. Measure resistance in Ω ohm range. For a pointer multimeter, zero adjustment is required every time the resistance range is changed. Zero adjustment is to put the red and black probes of a multimeter together, and then turn the zero adjustment knob to make the pointer point to the zero position. HFE is used to measure the current amplification factor of a transistor. Simply insert the three pins of the transistor into the corresponding holes on the multimeter panel to measure the hFE value. Note that the E, B, and C transistors of PNP transistors are P-type, N-type, and P-type semiconductors, respectively, while NPN transistors are exactly the opposite.
Using two wires to measure resistance is very convenient, but it can result in measurement errors. By using a multimeter with 4 wires and separate source and measurement terminals, this error can be almost eliminated. Unfortunately, adding additional leads and connections has increased the complexity of the measurement. You need to connect additional leads, and when changing from voltage to resistance, you may have to replace the clips and probes. Now, there is a new concept, 'Measuring Resistance with a Multimeter Simply and Accurately', which will teach you how to measure 4-wire resistance using only two leads.
