Method for selecting a multifunctional multimeter
The basic principle of a multimeter is to use a sensitive magneto electric direct current meter (microampere meter) as the meter head. When a small current passes through the meter head, there will be a current indication. But the meter head cannot pass through large currents, so some resistors must be connected in parallel or series on the meter head for shunt or voltage reduction, in order 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 welding or removing components, measure the temperature to prevent damage to the components.
2. Simultaneous measurement: In electronic testing, the signals we encounter for AC and DC components are not very pure AC or DC signals. We need to observe the total true effective value of the waveform (including the AC and DC parts) in order to analyze the power consumption of the circuit and identify the cause of some parts burning out due to DC imbalance.
3. dBm and millivolt value measurement: The so-called dBm value measurement refers to low-level measurement - dB value measurement. DB is generally expressed using this formula: dB=20LogV measurement/V reference. If the reference voltage of V is changed, through testing and comparison, we can measure the corresponding value, for example, to analyze the voltage gain of the voltage amplifier.
4. Peak holding: By using a multimeter to measure the true effective value, we can measure the instantaneous peak voltage of irregular AC signals with a width greater than 0.25 milliseconds, and automatically hold it, which is beneficial for identifying the cause of component and equipment damage.
5. △ Relative value measurement: With this function, we can perform relative value measurement, that is, we test the difference between the voltage or current and the reference voltage or current. The capacitance relative mode can remove stray capacitance from the reading.
