Five elements of choosing a digital multimeter
digital multimeter display
Generally speaking, most manufacturers use resolution numbers to represent the display capabilities of digital multimeters. The decimal places are the most significant digits that the multimeter can display. It is the ratio of the maximum possible value of a bit to the number of possible states. The higher the resolution, the more accurate the measurement. At the same time, the higher the resolution, the better the multimeter.
Digital Multimeter Counting
Because "resolution bits" often confuse users, manufacturers have begun to use "counts" to specify display capacity. The count of the digital multimeter refers to the maximum number that the multimeter can display before changing the range, and how many digits it can display in total, which will affect the accuracy of the digital multimeter.
Digital Multimeter Resolution
The resolution of a digital multimeter is the smallest change in the input signal that can change the output signal. When the range of a digital multimeter is reduced, the resolution increases. However, at the end of the day, you want your multimeter to display measurement readings at the best possible resolution.
Range of digital multimeter
When choosing a DMM, you need to know the minimum range, maximum range, and resolution you need. Most of today's DMMs offer auto and manual ranging measurements.
In an auto-ranging measurement, all you need to do is select the desired measurement function and let the multimeter automatically select the most appropriate range. In general, you should select autorange when you do not know the range of possible measurement readings. It is important to note that auto-ranging measurements are more time-consuming than manual-ranging measurements because the multimeter takes additional time to select and display the best measurement.
Manual ranging measurements are usually chosen when you know the expected measurements. Depending on your measurements, you can choose a range. If you don't know the measurements and want to use a manual range, it is recommended that you use the "step down" method. Start with the highest range and gradually reduce the range until the monitor reaches the optimum resolution.
Digital Multimeter Accuracy
DMM accuracy is not the same as monitor resolution. Accuracy refers to the maximum allowable error limit of the reading. Generally speaking, manufacturers will compare the accuracy of direct current voltage (DCV) with other manufacturers' specifications, because the accuracy of DCV is higher than other functions. The accuracy index can be expressed as ±(% of reading +% of range)
