Why isn't it suggested to compare results using a multimeter and a power analyzer?
If you want to choose the most commonly used instruments and meters for electrical engineers, I believe that the choice will be the multimeter. As the most commonly used instrument and meter, the multimeter has an irreplaceable position in the hearts of users, and it has also given users great trust in it. However, under various test environments, is the multimeter really infallible?
However, how much room for comparison is there between a multimeter and a power analyzer? What is right and wrong when there is a difference?
First of all, we need to be clear about the specific differences between the parameters of the multimeter and the power analyzer.
1. Bandwidth
Bandwidth is the key reference value for whether the signal under test can be accurately measured. The test bandwidth of most common multimeters is mainly around 40-70Hz. Benchtop multimeters of 1.5 digits and above can also test signals of several hundred kHz. The power analyzer will have an advantage in bandwidth. For example, the bandwidth parameter of PA5000H is 5M, and the bandwidth parameters of power analyzers at home and abroad are mostly set at 1M, 2M and other levels.
2. Sampling rate
The sampling rate is also a key parameter during the test. The sampling rate of the multimeter is not very high, and the desktop one is about several hundred k, while the sampling rate of the power analyzer is set at about 2M.
3. Accuracy
The difference in accuracy is mainly displayed on the handheld multimeter. The ADC digits used by our most commonly used multimeters are relatively low, and the accuracy of the test will also have some limitations; of course, for desktop multimeters, six and a half digits. 18-bit ADC, even a power analyzer with 0.01% accuracy is only an 18-bit ADC.
4. Synchronization
The user uses a multimeter to measure one indicator, voltage, current or resistance. If the test power needs to test the voltage separately, and then test the current for calculation; the channel of the power analyzer can test the voltage and current at the same time, and then calculate parameters such as power.
