BTW another good tip for those not familiar with how these instruments behave and how they actually work, is the Kelvin clips utilized. The inexpensive ones like supplied with the ET (we have a bunch of these, mostly for DC) are all independent cables, thus any flexure or movement can and will change the cable characteristics (capacitance). We often tape these down to the work bench for better repeatability.
The better Kelvin clips are the ones with the BNC adapter fixture, like the TH26011CS (comes with TH2830), these have a single cable that extends the first ~600mm, then a breakout box with individual Hc,Hp,Lp & Lc ~300mm shielded cables to the H and L Kelvin clips. Our experience is these types have less variation in use than the single cable types, and more convenient to use.
Best,