What is the difference between a digital source meter and a digital multimeter?

The SourceMeter does not have extremely high input resistance or extremely low current measurement capability like the Source Measure Unit. The SourceMeter is designed for applications such as routine testing and high-speed production testing. It is typically used in low- to medium-level testing and R&D laboratories.

Unlike a single-point measurement DMM, a source meter can be used to generate a set of current-voltage (IV) characteristic curves due to its built-in source function, which is very useful for testing semiconductor devices and materials; a DMM is a single current-voltage point.

The S source meter is the first domestically produced source meter with high precision, large dynamic range and digital touch that POSSIS has spent many years to build. It integrates multiple functions such as voltage and current input and output and measurement. The maximum output voltage is 300V, the minimum test current is 100pA, and it supports four-quadrant operation.

When used as a current source, the SourceMeter can be used with a nanovoltmeter to measure very low resistances by automatically reversing the polarity of the current source and correcting for offset errors.

Combining a high-precision source with DMM-like measurement capabilities, the SourceMeter's voltage and current measurement capabilities are superior in many ways to those of a DMM of equivalent accuracy. Unlike a voltmeter, which has an input impedance greater than 10GΩ across all voltage ranges, some DMMs have input impedances that drop to 10MΩ at the highest voltage range. Current measurements, in contrast, use a feedback ammeter rather than a shunt ammeter. The feedback ammeter has much lower impedance than a shunt ammeter, which means it is more like an ideal zero-impedance ammeter. In addition, for current measurements, the SourceMeter has a much wider dynamic range than a DMM.