National Instruments NI 4050 用户手册

The NI 4050 is protected against damage from voltages within 
±250 VDC or 250 V

rms

 in all ranges. You should never apply voltages 

above these levels to the inputs.

Figure 1-4.  Connecting Probes for Voltage Measurement

2.

Select the mode you will measure:

•

DC  Volts

•

AC  Volts

3.

Select the range for your measurement or autoranging:

•

DC Volts—± 20 mV, ± 200 mV, ± 2 V, ± 25 V, and ± 250 V

•

AC Volts—20 mV

rms

, 200 mV

rms

, 2 V

rms

, 25 V

rms

, and 250 V

rms

The value indicator displays the voltage measured.

Use the following procedure to measure 2-wire resistance using the soft 
front panel:

1.

Connect the test probes to a resistor as shown in Figure 1-5. To 
accurately measure the value of a resistor, make sure the resistor is not 
connected to any other circuits. Erroneous or misleading readings may 
result if the resistor you are measuring is connected to external circuits 
that supply voltages or currents or to external circuits that change the 
effective resistance of that resistor.

AC Voltage

Source

DC Voltage

Source

+
–

250 V
MAX.

LO

HI

250 V
MAX.

LO

HI