Error analysis of multimeter's voltage range measurement
When choosing a multimeter, in addition to considering the accuracy, it is also necessary to consider whether the range is suitable. In order to reduce the measurement error of the voltage range of the multimeter, the accuracy and range of the multimeter should be taken into account to ensure the accuracy of the measurement results.
The measurement error of the voltage block of the multimeter
1. The accuracy level of the multimeter
The accuracy level of the multimeter is generally divided into several levels such as 0.1, 0.5, 1.5, 2.5, and 5.
For DC voltage, current, AC voltage, current and other gears, the calibration of the accuracy (accuracy) grade is expressed by the percentage of the maximum absolute allowable error △X and the full scale value of the selected range.
The formula is: A%=(△X/full scale value)×100%
Error analysis of multimeter's voltage range measurement
2. Measurement error analysis
Test purpose: Use multimeters with different accuracies to measure the same voltage and see which one has the smaller error.
A 10V standard voltage is measured with two multimeters of 100V, 0.5 and 15V, and 2.5, which multimeter will have a smaller measurement error.
Measurement result:
From the above calculation formula:
1. The first meter is measured: the maximum absolute allowable error: △X1=±0.5%×100V=±0.50V.
2. The second meter is measured: the maximum absolute allowable error: △X2=±2.5%×l5V=±0.375V.
Comparing △X1 and △X2, we can see:
The accuracy of the first meter is higher than that of the second meter, but the measurement error of the first meter is larger than that of the second meter.
Summarize
When choosing a multimeter, don't just look at the accuracy, it's not that the higher the accuracy, the better.
With a multimeter with high accuracy, it is necessary to select the appropriate range, and only when the correct range is selected can the potential accuracy of the multimeter be exerted.
The above introduces the measurement error of the voltage range of the multimeter. A multimeter with high accuracy and a suitable range are the key factors to ensure the accuracy of the measurement results.
