DMM Measurement Defaults

NI Digital Multimeters

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DMM Measurement Defaults

The following table lists the default measurement settings for the NI 4070/4071/4072.

Function	Aperture	Auto Zero	ADC Calibration	DC Noise Rejection
DC 7½ digits¹	100 ms	ON	ON	High-Order
DC 6½ digits	100 ms	ON	ON	High-Order
DC 5½ digits	500 µs (NI 4070/4072) 500 µs² (NI 4071)	ONCE	OFF	Second-Order
DC 4½ digits	20 µs (NI 4070/4072) 50 µs (NI 4071)	ONCE	OFF	Second-Order
DC Auto Range	500 µs	ONCE	OFF	Second-Order
AC	Max (DC or 4/(minFreq))	OFF	OFF	N/A
AC Auto Range	Max (500 µs or 4/(minFreq))	OFF	OFF	N/A
Frequency	2/(minFreq)	N/A	N/A	N/A
Period	2 x (the maximum period)	N/A	N/A	N/A
Capacitance and Inductance	Inductance (only) at 10 kHz = 13.65 ms Inductance and capacitance at 1 kHz = 125.2 ms Inductance and capacitance at 91 Hz = 1.081 s	N/A	N/A	N/A
¹The default Number of Averages for the NI 4071 is 4. ²For the NI 4071, on the 5.5 DCV 100V range, use 1.6 ms.

By default, the Aperture time, Auto Zero, ADC Calibration, DC Noise Rejection settings for a measurement are chosen by the driver based on the configured measurement and resolution. These values are chosen to ensure accuracy for 6½–digit or 7½–digit measurements while not sacrificing performance at lower resolutions. For more information on a particular attribute, including how to configure a non-default setting, refer to Features. For AC, excluding Auto Range, the aperture is expressed as Max (DC or 4/minFreq). minFreq, or minimum frequency, is a user–programmable parameter with a default value of 20 Hz. Therefore, the aperture default is 200 ms.

The same applies for other user selectable values of minFreq. For example, on the NI 4070/4071/4072, if a minFreq of 1 kHz is selected then 4/minFreq = 4/1 kHz = 4 ms. In this case 4 ms would be used as the AC aperture for resolutions <6 digits. For resolutions >6 digits, 100 ms would be used.

To adjust the default aperture time, refer to Configuring Measurement Timing.

Default Settling Times

Function	Settling Time
DC V (100 mV–10 V)	1 ms
DC V (100 V, 300 V) (NI 4070/4072 only)	2 ms
DC V (100 V, 1000 V) (NI 4071 only)	5 ms
DCV Auto Range	2 ms
Resistance ≤1 kΩ	1 ms
Resistance 10 kΩ	5 ms
Resistance 100 kΩ	25 ms
Resistance 1 MΩ	100 ms
Resistance ≥ 10 MΩ	250 ms
Resistance Auto Range	50 ms
AC V DC coupled	3 µs
AC V AC coupled	1 s
Frequency/Period	500 ms
DC I	100 µs
AC I	3 µs
Diode	10 ms
Inductance (NI 4072 only)	3 µs
Capacitance (NI 4072 only)	3 µs

To adjust the default settling times, refer to Configuring Measurement Timing.

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