What is the resolving power (resolution) of a multimeter?
Digital multimeter in the lowest voltage range on the last 1 word corresponding to the voltage value, called the resolving power, which reflects the sensitivity of the instrument is high or low.
The resolving power of digital digital instrumentation with the increase in the number of display bits and improve. Different digits of the digital multimeter can achieve the highest resolving power indicators are different, for example: 31/2 digits of the multimeter 100μV.
The resolving power of a digital multimeter can also be displayed in terms of resolution. Resolution is the percentage of the smallest digit (except zero) and the largest digit that the meter can display.
For example, the general 31/2 digital multimeter can display the smallest number of 1, the largest number can be 1999, so the resolution is equal to 1/1999 ≈ 0.05%.
It should be noted that resolution and accuracy belong to two different concepts. The former characterises the "sensitivity" of the instrument, i.e. the ability to "identify" small voltages; the latter reflects the "accuracy" of the measurement, i.e. the degree of consistency between the measurement results and the true value.
The two are not necessarily linked, and therefore can not be confused, and should not be mistaken resolution (or resolution) is similar to the accuracy depends on the instrument internal A/D converter, the function of the converter to the integrated error and quantisation error.
From the measurement point of view, resolution is a "virtual" indicators (and measurement error has nothing to do), accuracy is the "real" indicators (it determines the size of the measurement error). Therefore, arbitrary increase in the number of display bits to improve the resolution of the instrument is not obtainable.
4.Measuring range
In the multi-function digital multimeter, different functions have their corresponding maximum and minimum values can be measured. For example: 41/2 digit multimeter, DC voltage test range is 0.01mV ~ 1000V.
5. Measurement rate
The number of measurements per second of the digital multimeter on the measured quantity is called the measurement rate, and its unit is "times / s". It mainly depends on the conversion rate of the A/D converter.
Some handheld digital multimeter with the measurement cycle to indicate the measurement of the speed. The time required to complete a measurement process is called the measurement cycle.
Measurement rate and accuracy indicators there is a contradiction, usually the higher the accuracy, the lower the measurement rate, it is difficult to balance the two. To solve this contradiction can be set in the same multimeter with different display digits or set the measurement speed switch:
Add a fast measurement file, which is used to measure the faster rate of the A/D converter; by reducing the number of display bits to significantly increase the measurement rate, this method is currently applied more common to meet the needs of different users of the measurement rate.
