Izvēle princips of multimetrs
1. Nolasījums precizitāte of rādītājs skaitītājs ir slikts, bet process of the pointer swing is more intuitive, and its swing speed range can sometimes objectively reflect the size of the measured (piemēram as mērīšana the sever jitter); the reading of the digital meter is intuitive, but the process of digital change looks messy and not easy to watch.
2. There are generally two batteries in the pointer meter, one is low voltage 1.5V, the other is high voltage 9V or 15V, and the black test lead is positive terminal relative to the red test lead. Digital meters usually use a 6V or 9V battery. In the resistance file, the output current of the test pen of the pointer meter is much larger than that of the digital meter. The R×1Ω file can make the loudspeaker make a loud "da" sound, and the R×10kΩ file can even light up the light-emitting diode (LED).
3. In the spriegums diapazons, iekšējais pretestība of the pointer meter is relatīvi mazs salīdzināts ar the digital meter, and the measurement accuracy is relatīvi slikts. Daži gadījumi ar augstspriegums un mikro strāva nevar pāra būt izmērīts precīzi, jo tā tā iekšējā pretestība būs ietekmēs ķēde zem tests (piemēram piemērs, kad mērīšana paātrinājums posms spriegums of a TV attēls caurule, the izmērītā vērtība būs būs daudz zemāks nekā faktiskā vērtība). Iekšējā pretestība of the spriegums diapazons of the digital meter is very large, at least in the megohm level, and ir little effect on the circuit under test. Tomēr, the extremely high output impedance makes it sususible to the influence of induced spriegums, and the measured data may be false in some occasions with strong electromagnetic interference.
4. In short, pointer meters are appropriateable for the measurement of analog circuits with relatīvi high current and high voltage, such as TV sets and audio amplifiers. It is appropriateable for digital meters in the measurement of low-voltage and low-current digital circuits, such as BP machines, mobile phones, etc. It is not unique, and pointer tables and digital tables can be selected according to the situation.
