Which type of multimeter is good for professional electricians to use
The measurement error of the pointer multimeter is large and the conversion rate is slow, but the charging and discharging display of the measuring capacitor is intuitive. The AC voltage range adopts half wave rectification (diode rectification), so the measurement error of the pointer multimeter in the AC voltage range is large because the AC voltage range adopts half wave rectification, So, the AC voltage range of a pointer multimeter measures the average value of AC power because the measured AC signal is rectified by a half wave rectification after being divided by a voltage divider, which reflects the average value of AC power. The input impedance of a pointer multimeter is not as high as that of a digital multimeter, and its sensitivity is not as high as that of a digital multimeter. However, professional electricians still recommend the MF-47 pointer multimeter, The new MF-47 circuit design adds varistors as overvoltage protection components to the resistance and current ranges. Some MF-47 and MF-47 are not suitable for measuring AC power for a long time, as they are prone to faults such as burning the voltage divider resistor at the lowest level of AC voltage range and rectifier diodes in the rectifier, which can cause large measurement errors in AC voltage range or failure of all levels of AC voltage range, (Burning out the lowest voltage divider in the series voltage divider in the AC voltage range, i.e. the 38.3K resistor connected to the AC 10V range, will result in the failure of all gears in the AC voltage range. Generally, burning out one of the two rectifier diodes in the rectifier in the AC voltage range will result in a large measurement error in the AC voltage range or a failure in the AC voltage range.) Or, in other words, poor contact of the gear switch, Or the short circuit of the gear switch can cause the burning of the voltage divider resistor or the burning of the rectifier diode to cause AC voltage shift faults, because current gear switches are all PCB switches.
It can measure AC power, but it is not suitable for long-term measurement. The main purpose is to determine whether the 220V or 380V voltage is normal. However, if AC power is frequently or for a long time, there may be an impact on the voltage divider and rectifier diode of the MF-47 AC voltage range. I have already specified the faults that are prone to occur in the AC voltage range of the MF-47 pointer multimeter mentioned above.
