In Episode 7 of "Corn College TV," Season 2, Missy Bauer answers a farmer’s question on how to measure tillage depth.
"I take two tile probes and push on where the shank ran. Then take the second where you haven’t run, and come in from the side where the ground is level. Push underneath and have it intersect the other probe. Measure from that point to the tip of the probe. That’s your actual measurement," she says.
See her explain more and why measuring tillage depth properly is important in this episode: