GW Instek GSM-20H10 is a precision source measure unit that provides highly stable DC power and instrument-grade 6½-digit multimeter measurements. GSM-20H10 provides four-quadrant operation of ±210V/±1.05A/22W. The first and third quadrants operate as power supplies to supply power to the load. The second and fourth quadrants function as loads to consume power internally. Voltage value, current value and resistance value can be measured while operating the power supply or load function with an accuracy of 0.012% and a resolution of 1µV/10pA/10µΩ.