Resistograph

[MasterBlaster]

That, along with the chips: they can speak volumes.

 

[flushcut]

So when the bar is in the tree and you stop pulling chips that's bad?

 

[sotc]

Or if the chips are soft or powdery

 

[Bounce]

I've seen 3 resistograph demonstrations now, and was thoroughly impressed every time. There is a local arborist around here who has one. He keeps quite busy with it by sub contracting the service to all the other arborists in the area.

 

[gf beranek]

Butch said it right. It's the feel of the cut and the color and textures of the chips that tells the story.

The resistograph recordeds the feel of the cut in a linear graph as its bit bores through the wood. The bit itself is feed into the tree under a constant pressure. And so in uniform wood the graph line is practically flat, but annual rings are still visible in the graph. That is a cool feature.

When the bit enters unsound wood and hollows the graph shows spikes in the feed of the cut All very accurate in measure. However well the device works the data that it presents is still left up to interpretation.

And a misdiagnosis that results in the removal of a sound tree could bite you.

 

[Paul B]

and the thing I have heard at each demo I have seen (3), it only measures the decay at the exact spot you probe, nothing proven for a spot 2 inches left, right, up or down... which in insurance terms is not too great. But its better than guessing, that' for sure.

 

[OTGBOSTON]

I know a guy who buys long thin drill bits, the kind they use for testing wooden ship hulls. It's a cheap alternative.

Like Paulie points out you're only gonna be able to guesstimate with the resistograph or a drill bits.

 

[sotc]

The problem with a regular drill is theres no read out, only the operator knows what he felt where as with the consistent pressure of the resistograph and the print out, results can be shared, re examined and seconded or questioned

 

[OTGBOSTON]

Understood

5g's or 5 bucks

One of our neighboring (wealthy) towns has one. The Arborist there is good about sharing it when we need it. I've only ever used it to confirm what I already knew....

Definately a good tool to have especially if you could sub out to other tree co's

 

[Blinky]

I wonder if they're used very often for determining age of a tree?

 

[OTGBOSTON]

I think thats a different tool.

 

[Blinky]

I know you can core a tree and count rings but in a temparate zone you should be able to discern early wood from late wood on the graph... it would do less damage and be easier to share the results.

 

[gf beranek]

The resistograph can show growth rings very accurately. The density of the wood between seasons is very distinguishable.

 

[TreeDimensional]

That depends on the species of tree your looking at:ring porous or diffuse pourous species. Growing conditions can also determine ring thickness. I saw a piece of Sitka spruce the other day a magnifying glass was needed to see the rings period.

 

[Blinky]

Yep, I see shortleaf pines like that. The only way to count them is to do fine sanding and/or staining.

 

[Burnham]

I use my increment borer...gives a core sample that you can examine, photograph, document, and save as physical evidence.

 

[Bermy]

There is also the debate over whether the bore hole will significantly breach a CODIT barrier and possibly lead to spread of decay...

We were shown even a scan from one of those non invasive 'radars', where sensors are placed around the trunk, hooked up to each other and a computer, tapped with a hammer and the results interpreted and printed out. You would have thought the tree was reasonably ok, maybe a shorter inspection interval, they took the tree down, saved a slice and it was WAY more decayed than the scan indicated...the tree was leaning over a footpath in a large public botanical garden!
I think the point was made to show us not to be eager beavers and skip the accumulation of experience and knowledge just because there is a cool piece of technology available to tech savvy newbies.

 

[tophopper]

Here's a tree we took down a few weeks ago.....

We had to use the resistograph to show the client why we will only remove this tree, and why we want to drive our bucket truck across the yard to remove it, rather than climb it.

 

[tophopper]

Its a great tool to have if you can afford one. It will take some time for you to see the return (depending how you wanna look at it).



It really is merely a tool for you to show your client what you already know about their tree from years of education and experience.

 

[OTGBOSTON]

It really is merely a tool for you to show your client what you already know about their tree from years of education and experience.

 

[Blinky]

Tree tomography isn't there yet but I'm confident it will happen... if we don't run out of helium first.

Decay patterns are pretty easy to understand, the problem is knowing how much sound wood is present and where it is. I'm terrified by butt rot and root decay. You can't see it, you can't measure it... only guess at it if you're around at the right time of yearto find fruiting bodies.

I looked at a red maple this weekend that's almost identical to the one that crashed on me, bad spot too, top has to come out before it can fall. I'll bet my 440 the root base is decayed... it's either highline it or crash it onto a fence.

 

[sotc]

That would likely be our main use here Chip, we get alot of root rot in our native oaks. I remember a lady saying, 'but it was so healthy, look at the leaves' while the crew was removing the tree from her car. The wood is often sound a foot off the ground and can be nearly non existent at or just below grade

 

[treesandsurf]

We've got a couple of guys here that own resistographs and even one guy that has a tomograph. When I get a sketchy tree I'll rent or borrow to use. Just drilled these three norfolk pines a little over a week ago. These guys can look totally solid and fall over with the whole inside rotted out from termites. The client wanted to show her neighbors the tree was solid, so wrote up a short letter with the charts.

jp

 

[gf beranek]

There's money to be made with the tool for sure. Through more liability issues.

It's been some time, bout 6 years, but the last I heard was about 5 G for the tool. Is this so today?

 

[Paul B]

yup, roughly.