National Instruments NI 5102 用户手册
Chapter 3
Digitizer Basics
© National Instruments Corporation
3-11
Figure 3-8. Probe Compensation Comparison
Active and Current Probes
You can also use active probes and current probes with digitizers
and DSOs.
and DSOs.
Active probes, such as differential and field-effect transistor (FET) probes,
contain active circuitry in the probe itself to reject noise and amplify the
signal. FET probes are useful for low-voltage measurements at high
frequencies and differential probes are noted for their high common mode
rejection ration (CMRR) and nongrounded reference.
contain active circuitry in the probe itself to reject noise and amplify the
signal. FET probes are useful for low-voltage measurements at high
frequencies and differential probes are noted for their high common mode
rejection ration (CMRR) and nongrounded reference.
Instead of using a series resistance in the loop to measure current, current
probes magnetically measure AC and/or DC current flowing in a conductor.
This lack of series resistance causes very little interference in the circuit
being tested.
probes magnetically measure AC and/or DC current flowing in a conductor.
This lack of series resistance causes very little interference in the circuit
being tested.
Probe Adjustment Signal
Probe Adjustment Signal
Probe Adjustment Signal
Proper Amplitude of a
1 MHz Test Signal
Reduced Amplitude of a
1 MHz Test Signal
Increased Amplitude of a
1 MHz Test Signal
a. Compensated Correctly
b. Undercompensated
c. Overcompensated