Here's a simple technique to utilize the Bode Function to create some nice Impedance Plots of various capacitors.

The idea is to have the scope plot Ch2/Ch1, or Vo/Vi as it does with the Bode function. Using an external AWG (SDG2042X) to create the stimulus under LAN control from the SDSX+, place the AWG output signal thru a reference resistor R (1K 2W 1% in our case). The DUT capacitor is placed from the Resistor to Local Ground, and Ch1 senses the AWG side of R and Ch2 senses across the DUT.

Here's a little math behind this, Vo is the voltage across the DUT and Vi is the voltage from the AWG source.

Impedance of DUT Z = Vo/I, where I is the DUT thru current.

I = (Vi-Vo)/R, where R is the sense resistor

Z = Vo/[(Vi-Vo)/R] = R/( Vi/Vo -1), if Vi/Vo is >> 1, then

Z ~ R(Vo/Vi) and Vo/Vi is what the Bode function plots.

So simply scaling the Bode Function dB scale by R revels the ~ Magnitude of DUT Impedance and the Phase is as indicated.

For the magnitude in ohms |Z| ~ R[ 10^(dB/20)], C ~ 1/(|Z|*2pi*F)

Here's a few capacitor examples:

Edit: Added (Calculated from graphs and Tonghui LCR Meter TH2830 Measured values).

#28 680uF Electrolytic (634uf, 641.5uF @ 100Hz)

#31 470uF Polymer (459uF, 469uF @ 1KHz)

#32 10uF Mylar (9.59uF, 9.72uF @ 1KHz)

#33 5uF Polypropylene (4.89uF, 4.84uF @1KHz)

#34 0.1uF Polystyrene (poor quality)

Added these:

#35 1uF Mylar (981.3nF, 994.5nF @ 10KHz)

#37 2uF Polypropylene (1.985uF, 1.975uF @ 10KHz)

#38 10nF Polystyrene (10.28nF, 10.086nF @ 100KHz)

#39 100nF Disc Ceramic (95.9nF, 92.81nF @ 10KHz)

The SDSX+ does a respectable job with it's nice low noise front end and good overall dynamic range, and the Bode Function is "Icing on the Cake"

Anyway, hope some folks find this interesting.

Best,