DC Current

Configure DC current measurements.

Range

Use Auto to automatically select the range, or select a fixed manual range. Click the Auto-Select button to auto range for one measurement and then return to the fixed manual range mode. Manual ranging results in better measurement speed, since the DMM does not have to determine which range to use for each measurement. If the input signal is greater than can be measured on the selected range:

• In line chart view, the overload indication (+OVLD or -OVLD) is displayed above the chart and the overload reading is plotted off the top (+OVLD) or off the bottom (-OVLD) of the chart.
• In histogram view, the overload indication (+OVLD or -OVLD) is displayed above the histogram and the reading is placed in an outer bin to the right (+OVLD) or to the left (-OVLD) of the histogram. Outer bins are shown in red.

Calibration

Click the Auto Calibrate button to perform an automatic calibration of the instrument to compensate for temperature drift and maintain measurement accuracy.

Aperture

Set the aperture time for the measurement in number of power-line cycles (NPLC) or in seconds (Aperture)/ resolution (Resolution). To obtain normal mode (line-frequency noise) rejection, select an integral number of power-line cycles (1, 2, 10, or 100 NPLC). For more information, see Aperture Time and Resolution.

Auto Zero

Enable autozero for all readings (select On), enable for one reading (select Once), or disable (select Off). Autozero subtracts a zero reading from each subsequent measurement.

Null State

Enable or disable the null measurement feature. This feature measures the difference between a stored null value and the input signal; Result = reading – null value. Select Value check box to enable this feature and enter a null value. Some DMMs have an Auto-Select selection. When Auto-Select is selected, the first reading taken is used as the null value for all subsequent measurements for this measurement function.