What Is the Accuracy of a Digital Multimeter?
A digital multimeter is currently a common type of digital instrument, with powerful measurement capabilities that greatly surpass analog multimeters. It is also convenient to carry, easy to operate, and has powerful functions; Understanding the basic characteristics of a product is a prerequisite for using a multimeter well. Next, the editor will talk about the 9 basic functions of a multimeter - accuracy;
Accuracy of digital multimeter
The accuracy and error of a multimeter are inseparable, and digital multimeters inevitably produce errors when measuring again. The measurement error of an instrument is one of its important technical features, and the accuracy of an instrument is its measurement error limit, which means that under specified conditions, the measurement error of the instrument will not exceed the given error range. Therefore, measurement error refers to the degree of difference between the measured value and the true value, which is relative to a certain measurement result, while the accuracy of an instrument is relative to a certain instrument.
The measurement error of an instrument consists of two parts, fixed error and additional error, namely the error that does not depend on the measured size and the error that depends on the measured size. The former is called fixed error, the latter is called additional error, and the total error is the combination of these two errors.
The accuracy of a digital multimeter is the combination of systematic and random errors in the measurement results. It represents the degree of consistency between the measured value and the true value, and also reflects the size of the measurement error. Generally speaking, the higher the accuracy, the smaller the measurement error, and vice versa.
The additional errors of digital multimeters include errors in additional resistors (voltage dividers), conversion errors from input to DC voltage, and errors in the basic voltage of A/D converters; The fixed error is mainly caused by factors such as quantization error, zero drift, and internal noise of the A/D converter. The former term is generally referred to as reading error, while the latter term is referred to as full-scale error.
