Why does the multimeter have bandwidth?

Multimeter bandwidth introduction
In the world of measuring instruments, digital multimeters are the most common, and digital multimeters measure objects (voltage, resistance, capacitance). Today is to say that the multimeter measures the bandwidth of the voltage. The bandwidth unit is expressed as (Hertz: English stands for Hz). The bandwidth indicates the bandwidth that the device can measure effectively and accurately. The so-called bandwidth is -3db bandwidth, -20log (output voltage / input voltage) = -3db (log base is 10), can be calculated: input voltage / output voltage = 0.7; multimeter is accurate for 20Hz signal response When the voltage is gradually increased, the output will change due to the different response characteristics of the multimeter to different frequency signals. When the output voltage = 0.7 times the input voltage at a certain frequency, it indicates that the signal has reached the -3db bandwidth of the multimeter.