In light of the recent tutorial on getting to a 100% calibration, wanted to post my cheaper method using stuff you can buy at Home Depot and Target. Good luck!
I’ll make one recommendation that you move one of the panels down to cover the area from floor to the bottom of the other panel, enabling you to sample all elevations at once, which will likely save you some time compared to gathering samples from the upper volume, then adjusting and getting samples from the lower volume.
This is a bit in the weeds, but one advantage that the articulating and locking grip gear provides is the ability to angle and lock each chart individually to face the midpoint between the two targeted sensors, making each of them less likely to get filtered out by the Sheer Angle filter. I suppose if you are targeting higher sensors, you could stuff something behind the panels to angle them upward a bit.