If you choose Impedance and Phase for the display, you can use the
button on the Spectrum display to show the Capacitance or Inductance at
the Tracer position (depending on phase).
Use this panel to measure impedance, capacitance and inductance vs
frequency. Three measurement setups are supported labelled A-C in the
Circuit control. In addition you use this panel when doing Fixture
Calibration. These are the setups:
Controls are:
R ref - which sets the reference resistor when using probes. A good
starting value is 50 ohm - to match the sig gen impedance. For low esr,
or large (>10uF) Capacitors use 10 ohms. Same for low value Inductors
(<10 uH).
L -C Display. Choose Resr, Q/D Factor or Phase as appropriate to be
plotted to Chan B. Use Fit after plotting to see the whole amplitude
range. Position the tracer on the plot you wish to expand, and then use
Ctrl Up/Down to zoom in/out on that tracer position. Use Tab to switch
between channels.
When using Coax, Circuit lists three coax connection circuits.
Rref Term (RrT) - sets the measurement termination resistor value for
Circuits A and C if you are using coaxial cables. Coax is best when you
are working above 10 MHz. Coax should be terminated for maximum
accuracy. 50 ohms is a good value.
R ref - which sets the reference resistor for Circuit B. A good starting
value is 50 ohm - to match the sig gen impedance. For low esr, or large
(>10uF) Capacitors use 10 ohms. Same for low value Inductors (<10
uH).
R Cal is used as a calibration resistor and replaces Zuut when calibrating
the jig. See the calibration section below.
C Open is used to compensate for the jig open circuit capacitance.
Typical values are 0.5 - 1pF.
Circuit and Measurement Jig Discussion
For low frequency applications (< 10 MHz) you can use the scope probes to
directly connect to the device under test. For High Frequency (>10 MHz) we
recommend using a 50 ohm terminated coaxial cable connected test system.
See the 'Impedance Measurement with FRA' video on
www.cleverscope.com/videos.
Circuit C results in the greatest accuracy as both the Rref and Zuut voltages
are measured independently in the frequency range up to 1 MHz. Above
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