How to choose a multi-function multimeter
The basic principle of the multimeter is to use a sensitive magnetoelectric DC ammeter (microampere meter) as the meter head. When a small current passes through the meter head, there will be a current indication. However, the meter head cannot pass a large current, so some resistors must be connected in parallel or in series on the meter head to shunt or lower the voltage, so as to measure the current, voltage and resistance in the circuit.
1. Temperature measurement: During electronic maintenance, a multimeter with this function is convenient for you to check the heating degree of electronic components. For example, when soldering and removing components, measure the temperature to prevent damage to components.
2. Simultaneous measurement: AC and DC components In electronic testing, the signals we encounter are not very pure AC or DC signals, we need to observe the total true RMS value of the waveform (including AC and DC parts) in order to analyze the circuit The amount of power consumption, to find out the reason why some parts burn out DC imbalance.
3. dBm and millivolt measurement: the so-called dBm value measurement, that is, low-level measurement----dB value measurement. dB is generally expressed by this formula: dB=20LogV measurement/V parameter. If the V reference voltage is changed, we can measure the corresponding value by testing and comparing: for example, it is used to analyze the voltage gain of the voltage generator.
4. Peak hold: Use the multimeter to measure the true effective value. With this function, we can measure the instantaneous peak voltage of the irregular AC signal with a width greater than 0.25 milliseconds, and automatically hold it, which is conducive to finding the cause of component and equipment damage.
5. △Relative value determination: With this function, we can perform relative value determination, that is, we test the difference between the voltage or current and the reference voltage or current, and the capacitance relative mode can clear the stray capacitance in the reading.
