The RINNTECH Resistograph 4452-S is the best drill resistance measuring device on the market for use with tropical hardwoods.

What's so good about it?

1. It has automatic adjustment for different wood densities.
2. It can handle extremely dense wood such as Casuarina equisetifolia, Acacia confusa, and Litchi chinensis
3. Automatic protection against damage.  If it receives too much resistance during drilling, for example hitting cement or metal in a tree, it will automatically reverse.
4. Its lightweight, all of the weight is in the battery pack which can sit conveniently on the ground.
5. Water resistant - Measurements can be done during light rain
6. Everything is automatic.  You can lock on the drill and when it reaches the end, it will automatically reverse itself.
7. A convenient light on the top shows you the drilling depth, so measurements can be done even in low light situations.
8. The measurement prints out in the battery pack and the paper does not need to be changed after every drilling.  In addition, prior to each drilling, the device prints the date, time, and reading number at the top of each reading.