Are digital multimeters going to replace analogue dial multimeters?
In addition to the two different displays, there is a big difference, is the internal resistance is different, digital multimeter than pointer multimeter internal resistance is higher than more than two orders of magnitude, the internal resistance of the best pointer meter, are not as high as the internal resistance of the most inferior digital meter. This is one of the reasons why digital meters are more accurate than pointer meters.
However, high internal resistance, sometimes is not necessarily an advantage, for example, in resistance measurement, the multimeter must provide current flow through the resistor, in order to derive the resistance value by measuring the resistance voltage, this time the digital meter tends to provide a very small current, is the level of microamps, the pointer meter is the level of milliamperes, if you use the resistance file to measure the leakage resistance of the capacitor, the digital meter this point of the current to make the microfarad level of capacitance is full that is Too slow, almost impossible to measure, while the pointer meter can quickly give the capacitor full of electricity to measure the leakage or not.
But this small output current characteristics of the digital table in the online measurement of resistance value is convenient and accurate and unique, due to the output current is small, the surrounding online capacitors, inductors, transistors and so on, the shunt is very small, so the online measurement of resistance resistance value is more accurate, save things, generally do not have to weld open the soldering point to measure the resistance resistance value of the resistance is normal.
Another example is the measurement of non-linear device PN junction good or bad, the current provided by the digital table is often a large difference with the actual operating current, the judgement will not be very accurate. At this point, the pointer meter is very good to use.
Two measuring tools, digital table in the production of measurement and control links, can be more to replace the pointer table. But in the field of technology development and maintenance, pointer gauge still has an irreplaceable role.
