How to add high impedance input to a Scope?

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Joined Mar 26, 2014
The Fluke 123 Scopemeter has a 1Mohm input impedance. The test requires a minimum 10Mohm input impedance. What could I buy or build to make the Fluke 123 work for the test?

I would like to capture and display a discharge waveform at somewhere between +3 volts to -3 volts. The typical time is milliseconds for the discharge.
I have successfully record the voltages with a Fluke 189 set to Fast while measuring the decay of a 120 Hz voltage. I would like to be able to visualize the waveform around the minimum voltage. I am looking to see (1) if there is an inductive spike in the curve, and (2) the minimum voltage of the spike.

The attached waveform is from some equipment which is AFAIK no longer available. (The image is a photo of the scope's screen which was faxed to me. I added the "volts" text.)