It has an accuracy of +/- 6"?

Seriously, it can be useful once you build a "sense of touch" with practice. Like learning how hard to hit the ball to lob it over a tennis opponent's head.<----simile. :)

Actually, that's an analogy. A simile would involve a comparison, such as, "crazy as an outhouse rat."

Actually, that's an analogy. A simile would involve a comparison, such as, "crazy as an outhouse rat."

I stand corrected, but I did use "like".

Use of the word "like" does not indicate that the structure would necessarily be a simile. Nor does a simile require the use of the word "like," as the simile above that I wrote didn't use it.

It's really a very common mistake, akin to using "literally" when one means "figuratively" (which I will not accept no matter what the Oxford English Dictionary says in 2016). Unless you're educated on the finer points of such things, it's an easy error to make, and not really a big deal. It's merely a small pet peeve of mine.

I think finger test is more accurate than screwdriver test. But probably even better would be to insert a metal tool wide enough for me to insert finger and test soil.

actually I only us test finger for contained plants. Sod looks wimpy when it's dry and that's enough data for me to act on

Even my attempt at self deprecating humor has failed.

Somehow the finger test seems appropriate.

Yes. Yes, it did.

Back to the topic, nobody has a calibrated screwdriver that tells exactly what force is required to push 1 inch, 2, or 3-6 inches. It is a relative test. Try it when the soil is dry and again when it is wet. Spray with shampoo and give it 3 weeks before you do the screwdriver test again.

One could buy or build a penetrometer, but a moisture metering probe would be optimal. $$$