Chapter 1 Taking Measurements with theNI 4050
© National Instruments Corporation 1-7 NI 4050 User Manual
Figure 1-5. Connections for Resistance Measurement
2. Select 2-wire resistance mode.
3. Select the range for your measurement—200 Ω, 2 kΩ, 20 kΩ, 200 kΩ,
2 MΩ, 200 MΩ, or autorange.
The value indicator indicates the resistance measured. See the 2-Wire
Resistance Measurements section of Chapter 2, NI4050 Operation, fo r
more information on 2-wire resistance measurements.
Measuring the Voltage Drop Across a Diode
The NI 4050 can excite a device under test and read the resulting voltage
drop. Diode mode is useful for testing diodes. Use the following procedure
to measure the forward drop across a diode. Voltage up to 2V can be
measured in this mode.
1. Connect the test probes to a diode as shown in Figure1-6. To
accurately measure the forward voltage of a diode, make sure that the
diode is not connected to any other circuits. The NI 4050 biases the
diode with a current of 100 µA and measures the resulting voltage
drop. Diode measurements are made with a fixed range of 2.0V.
Figure 1-6. Connecting Signals for Diode Test
Resistor
250 V
MAX.
LO
HI
Diode
+
–
100 µA
250 V
MAX.
LO
HI