Referenced and nonreferenced single-ended measurement systems are similar to grounded sources in that the measurement is made with respect to ground. A referenced single-ended (RSE) measurement system measures voltage with respect to the ground, AIGND in the figure, which is directly connected to the measurement system ground. The following figure shows an 8-channel referenced single-ended measurement system.
DAQ devices often use a variant of the referenced single-ended measurement technique, known as nonreferenced single-ended (NRSE). The following figure shows an NRSE system.
In an NRSE measurement system, all measurements are still made with respect to a single-node analog input sense (AISENSE), but the potential at this node can vary with respect to the measurement system ground. The previous figure illustrates that a single-channel NRSE measurement system is the same as a single-channel differential measurement system.