When I first heard of the Smart Thumper app for the iPhone, I thought, “What a cool thing! Testing wood with your phone!” But I couldn’t help wondering if this was more of a toy than a tool. So, I downloaded the app to try it out.
First off, a little background. The Smart Thumper app was developed by the Mississippi State University Department of Sustainable Bioproducts. It is intended to be a serious tool to make it easier to measure the strength of wood using the built-in capabilities of a smart phone.
“Smart Thumber uses the built-in microphone or accelerometer to detect vibration and estimates the dMOE of lumber and other wood sizes,” according to the instructions that you can download with the app.
There are two basic testing strategies. One uses the motion-sensing capabilities of the phone to tap test the wood. The other method uses the phone’s microphone to measure the sound generated when you tap the end of the wood with a hammer.
The capabilities of the app are both sophisticated and limited at the same time. They are sophisiticated in the level of data you can record, save and share by email. But they are limited in that the tool is obviously designed more with construction lumber in mind.
How it works
To test a board, you set it up on a couple of sawhorses according the instructions provided. Then you measure the board as to width and depth (cross-section) and length and enter that data. You can also enter the board weight. Because it is set up for lumber, it has built-in parameters starting with 8-foot lengths, but you can select Other to manually type in any length. You also are supposed to type in a wood species, but the available menu includes only common construction species such as Southern yellow pine, Douglas-Fir, and spruce-pine-fir (SPF).
Then you test. For vibration tests, you lay the phone in the center of the board and tap the board with your hand to make it vibrate. For tap tests, you hold the phone off the end of the board and strike the board with a hammer.
Results are both numerical, identifying the frequency and stiffness data, and in color-coded levels of 1-3. You can save and email all of your testing records, so you can more easily compare samples.
Toy or tool?
I found the testing fascinating and surprisingly consistent when testing the same board over and over, so I’d definitely say it’s more tool than toy. But the species limitation was frustrating. I immediately wanted to use the app to test all sorts of hardwood samples. I could do that, but I suspect the results would be more accurate as comparison with each other than as empirical numerical results.
Still, for a mere cost of $4.99 in the iPhone App Store, what have you got to lose? Unfortunately, it is not yet available for Android devices. I’m going to start testing all sorts of samples, and I will likely report back later with more results.
Have something to say? Share your thoughts with us in the comments below.