Why Multimeter Bandwidth Is Important
In the world of measuring instruments, digital multimeters are the most commonly used, and digital multimeters measure objects (voltage, resistance, capacitance). What I want to talk about today is the bandwidth of the multimeter to measure the voltage. The bandwidth unit is expressed as (Hertz: the English representative is Hz). The bandwidth indicates the frequency bandwidth that the device can effectively and accurately measure. Generally speaking, the bandwidth is -3db bandwidth, -20log (output voltage/input voltage) = -3db (log base is 10), it can be calculated: input voltage/output voltage = 0.7; the multimeter is accurate to the 20Hz signal response Yes, when the voltage is gradually increased, the output will change due to the different response characteristics of the multimeter to different frequency signals. When a certain frequency, the output voltage = 0.7 times the input voltage, it means that the signal has reached the -3db bandwidth of the multimeter.
Why does a multimeter have bandwidth?
The first method is: when we measure the current, it is easiest to measure the model of the bandwidth. When the engineer adjusts the switch to the current level, connect the black and red wires to the input signal line on one side and the input signal line on the other side, and observe the current change. If there is a value, it means there is a signal, otherwise there is no signal.
The second method is: electricians can creatively use the current gear to detect the current between two or two wires (one dark color, one light color) of the network cable. If there is current in all four groups, there is a signal, otherwise there is no signal. .
Among the many multimeters, the bandwidth of the Fluke multimeter depends on the factors of different multimeter models (basic characteristics, readings, true RMS, DC accuracy,) to determine its bandwidth results. Generally there are (20KHz to 100KHz) ranging.
