Selection of Multimeter Pointer Meter and Digital Meter

Selection of multimeter pointer meter and digital meter
1. The reading accuracy of the pointer meter is poor, but the process of the pointer swing is relatively intuitive, and the amplitude of its swing speed can sometimes reflect the measured size objectively; the reading of the digital meter is intuitive, but the process of digital change looks very messy. Not easy to watch.
2. There are generally two batteries in the pointer watch, one is low voltage 1.5V, and the other is high voltage 9V or 15V. The black test pen is the positive end of the red test pen. Digital meters usually use a 6V or 9V battery. In the resistance mode, the output current of the test pen of the pointer meter is much larger than that of the digital meter. Using the R×1Ω file can make the speaker emit a loud “click” sound, and the R×10kΩ file can even light up the light-emitting diode (LED).
3. In the voltage range, the internal resistance of the pointer meter is relatively small compared to the digital meter, and the measurement accuracy is relatively poor. Some high-voltage and micro-current situations cannot even be measured accurately, because the internal resistance will affect the circuit under test (for example, when measuring the acceleration stage voltage of a TV picture tube, the measured value will be much lower than the actual value). The internal resistance of the voltage range of the digital meter is very large, at least in the megohm level, and has little impact on the circuit under test. However, the extremely high output impedance makes it susceptible to induced voltage, and the measured data may be false in some occasions with strong electromagnetic interference.
4. The pointer meter is suitable for analog circuit measurement with relatively high current and high voltage, such as TV sets and audio amplifiers. Digital meters are suitable for digital circuit measurement of low voltage and small current, such as BP machines, mobile phones, etc. It is not absolute, and pointer tables and digital tables can be selected according to the situation.