Model 2461 Interactive SourceMeter® Instrument Reference Manual Section 4: Source-measure considerations2461-901-01 A/November 2015 4-3Source voltageWhen you configure the instrument to source voltage, it functions like a low-impedance voltagesource that can limit current. The instrument can measure current or voltage. This configuration isshown in the figure below.Sense circuitry continuously monitors the output voltage and makes adjustments to the voltagesource as needed. The voltmeter senses the voltage and compares it to the programmed voltagelevel. If the sensed level and the programmed value are not the same, the source voltage is adjustedaccordingly.If you set the instrument to 2-wire sense, the voltmeter senses the voltage at the FORCE HI andFORCE LO terminals. If it is set to 4-wire sense, the voltmeter sense the voltage at the device undertest. Four-wire sense eliminates the effect of voltage drops in the test leads, ensuring that the exactprogrammed voltage is applied to the device under test.If you are sourcing and measuring the same function (for example, sourcing voltage and measuringvoltage), the measurement range is the same as the source range. You can use this feature whenoperating when source limits have been exceeded. When the source limits have been exceeded, theprogrammed source value is not reached. Thus, measuring the source lets you measure the actualoutput level. You can also use the source readback function to measure the actual output level. SeeSource readback (on page 2-130) for information.Figure 144: Voltage source configuration
