Which one has the highest accuracy if you want to buy a multimeter
For electrician friends, a multimeter is essential for its convenience and practicality. Many friends feel that accuracy is more important when choosing a multimeter, and even demand a precision of several thousandths. Actually, I think accuracy is not as important as you think for ordinary maintenance work, except for repairing certain precision circuit boards.
For example, measuring the voltage of a certain motor, which is 380V and 383V, does not have much effect on determining a line fault. Multimeters are not cutting-edge technology, and the errors of different brands of multimeter are not much different. I think what is more important than accuracy is that it has excellent quality, durability, is not easy to break, and does not drop the chain at critical moments.
Pointer and Number Tables
Multimeters are mainly divided into two categories: pointer meters and digital meters.
The pointer multimeter has low input impedance and accuracy, but it has strong anti-interference ability and can intuitively reflect size changes.
The digital multimeter has high input impedance, high accuracy, intuitive reading, and rich functions, such as measuring voltage, current, temperature, capacitance, and so on. Due to the use of instantaneous sampling in digital meters, it is easy to experience digital jumping.
If you are a beginner, I suggest starting with a pointer multimeter. Although you may find reading a pointer multimeter troublesome at the beginning, if you get used to it, you will fall in love with it. Many circuit tests actually do not require a reading at all, just look at the pointer deflecting that way. If it is a digital meter, it is necessary to compare the results before and after the measurement to know the circuit condition.
Both MF50 and MF47 are classic models of pointer multimeters, and MF47 is generally used for beginners and teaching electricians. As for the brand of the pointer multimeter, "Nanjing Jinchuan Electric Meter Factory (formerly Nanjing Electric Meter Factory)" is an old brand. Although the new model is not as solid as before and light in hand, the quality is also very good in the pointer multimeter and worth owning.
As for digital watches, the most common brand is the "Victory" brand multimeter, which is cheap and of decent quality. Models ranging from tens to hundreds of yuan are available. Novice friends who want to buy a digital watch can buy it because it won't hurt if it burns out. (Don't say you can pay attention, you can't burn a watch. I can say that old electricians have mostly burned a multimeter, just like swimmers have choked on water. I've only burned it once, haha)
If you want quality and accuracy, the "Fluke" brand multimeter can be said to be outstanding. It has good quality and high accuracy, but the price is also very beautiful. The minimum is one or two hundred yuan, and there are thousands of expensive ones available. If you take care of it, it won't be a problem for a few years or even more.
accuracy
When it comes to accuracy, we have to mention "three and a half" and "four and a half". So what do they mean? What does it have to do with accuracy?
Three and a half digits "indicates that the multimeter can display a total of 4 significant digits, with the last three digits displaying a total of 10 digits from 0 to 9. From right to left, the fourth largest digit is called a half digit because it can only display "1".
Similarly, 'four and a half digits' indicates that the multimeter can display a total of 5 significant digits, with the last four digits displaying a total of 10 digits from 0 to 9. From right to left, the fifth largest digit is called a half digit because it can only display "1".
For example
The actual voltage of a dry battery is 1.489213 volts. If a three and a half digit multimeter is used for measurement, its display result is 1.489V; If a four and a half digit multimeter is used for measurement, its display result is 1.4892V.
Give me another example
The actual voltage of one battery is 3.489213 volts. If a three and a half digit multimeter were used for measurement, its display result would have been 3.489V. However, the "three and a half" multimeter can only display a maximum of 1 from the fourth digit from right to left, but the actual voltage starts with 3, so the fourth digit from right to left cannot be displayed. The final result only shows three digits, which is 3.48V.
Similarly, if a four and a half digit multimeter is used for measurement, its display result is 3.489V.
