Difference between metered and digital multimeters
Multimeter is the most used test instrument in the maintenance electrician industry, you must master the use of the multimeter, understand the multimeter test principle. The electricians engaged in strong and weak electricity generally only use the AC and DC voltage file and the on-off test file, and seldom use the other files.
We know that maintenance electricians often need to measure the performance of various electronic components, we need to use the multimeter resistance, DC voltage, AC voltage, capacitance, diode and other gear measurements, to determine the faulty components.
Often see maintenance electricians use pointer multimeter, is deliberately show their deep experience in maintenance? Or is there another reason, what is the difference between a pointer multimeter and a digital multimeter? Let me tell you:
For the difference between the two kinds of table, that is really benevolent and wise, different views, today mainly talk about my views, look forward to your guidance.
Pointer multimeter is the use of a very sensitive magnetoelectric DC ammeter as a meter, in the test, when the magnet winding coil flowing through the DC current, the coil in the magnetic field of the permanent magnet and drive the pointer, so that the pointer stays in a certain position, the corresponding dial to give the corresponding readings, the mechanical zero used to correct the pointer zero error, in the absence of a signal will be adjusted to the pointer to the zero position.
Advantages: Pointer multimeter belongs to passive equipment (that is, no battery is installed in the multimeter can also work), high sensitivity, fast response speed, through the pointer swing, it can intuitively display the physical properties of the measured components.
Disadvantages: poor resistance to electromagnetic interference, inconvenient reading, poor shock resistance, need ohm zeroing when testing resistance, can only test the voltage above 0.5V, testing weak voltage accuracy is not enough, not convenient to carry.
Digital multimeter is equipped with internal integrated operational amplifier circuit, through the sampling of the measured components and equipment, the test results will be input into the internal A/D converter, counter, and then to the logic operation circuit operation, through the display window for display. Digital multimeter belongs to the active equipment, (the table does not install the battery can not work properly) Advantages: high precision, especially the test voltage can be accurate to 0.001V, (part of the multimeter), easy to read, anti-electromagnetic interference ability, easy to carry.
Disadvantages: slow response time, some semiconductor devices can not be accurately tested, can not test components leakage, etc..
