Thermal Imaging Camera's

[BootyArb]

Andrew,

 

I'm sitting on the fence on some of the thermal imaging stuff at the moment. As you say, thermography as a method of detecting defects has been peer reviewed time and again and seems to work well if used properly.

 

What hasn't been peer reviewed is the system promoted by Tree Projects Ltd. As I understand it this uses a very different method and incorporates a risk of failure protocol which also hasn't been peer reviewed.

 

I'd be very happy to be proved wrong though.

 

Yes, but as I understand it the two are independent of one another. Thermal imaging can be used with or without the ‘risk of failure protocol’, and as Marcus has pointed out, it is just as effective it you want to use it to support another risk assessment system of your choice.

 

Throwing the baby out with the bath water springs to mind…… don’t you think.

 

Come on guys, I thought the girls in the clubs were bad at bitching, based on gossip and rumor…..

 

It seams that arborists are far worse.

[Arborist Sites]

Yes, but as I understand it the two are independent of one another. Thermal imaging can be used with or without the ‘risk of failure protocol’, and as Marcus has pointed out, it is just as effective it you want to use it to support another risk assessment system of your choice.

 

Throwing the baby out with the bath water springs to mind…… don’t you think.

 

Come on guys, I thought the girls in the clubs were bad at bitching, based on gossip and rumor…..

 

It seams that arborists are far worse.

 

No, what it seems is people are trying to get simple questions answered and all is given is the same old blurb, there also seems to be a selection process used to avoid certain areas and or comments......

[Andy Clark]

There are a number of points here that are valid and should always be investigated fully before any product is launched.

 

Regarding the science behind how thermal imaging works and what it demonstartes this has been well established for around 40 years. The first publications on the relationships between surface temperature and the internal heat conduction and heat capacity were around the 1920's.

 

More recently I have submitted a number of publications on both the science of how it works and its application, as has Giorgio Catena. And there are lots of other more recent applications of thermal imaging in forestry. The university of Melbourne runs courses on its use with wood pests for example.

 

In terms of the overall system developed, it is not actualy a probability of failure system but what it can do is feed information into probability of failure methodologies for risk assessment but it can also feed into classification systems like Metheny and Clark or THREATS. With all tools there is a need for the data provided to be consistent woth the methodologies used to assess the trees.

 

VTA is essentially a methodology based on comparative statistics. You look at the tree and identify those variables, factors or attributes that are different form the population as a whole. Once these are identified there can be a need for further investigation, with thermal imaging the system uses the same methododlogy. The data from the thermal images is compared to what is considered normal for a tree population and is compared statistically. When it is proven that it is statistically significantly different from the rest of the population it is considered for further investigation, at this stage it is usually an invasive methodology. This separation of trees into classifications according to thier condition is just waht is achieved by THREATS and by VTA.

 

Comaprison with actual failures gives the benchmark for the relationship between the progression of the dysfunction detremined by the thermal image and the likelihood of failure. This can also be cross-referenced by comparisons between different populations such as sheltered woodland populations, exposed populations or urban populations. This can be achieved because you can sample so many trees. This has been submitted and accepted for publiction.

 

Incedently data from VTA should be treated in the same way. It should be collated and analysed to find out where the differences are and how individuals that fail are different from the rest of the population. If this isn't done then there is no scientific validity to any assumptions made about the hypothetical correlations between individual defects and the likelihhood to fail.

 

Also accepted for publication is the protocol that you can monitor changes in the thermal properties of wood to monitor recovery and decline. This can also be used to audit VTA methodologies. This allows in part quantification of the reduction in likelihood of failure brought about by an increased frequency of inspection. This cannot be done accurately by VTA alone but it means that ultimately you get an inspection regime that fits the required outcome rather than prophalactic inspection for the sake of it or restricted inspection because there is no justification for the increased expense. This is not to mention targeted inspection regimes and amny otherthings that can be introduced with TI

 

As for the idea that it is a tool that we don't need, as long as there are trees being needlessly removed we need a tool that will give us more information about the internal workings of trees. A great deal has been made about the non-invasive nature of thermal imaging, but it is also the kind of information given that is important. The conductivity and capacitance of wood are optimal when the wood fibre is intact and the cells are well hydrated. As water is removed and the fibres degraded, the thermal properties are reduced. This means that changes in the thermal reactivity of wood give us information about where cells are well hydrated and well organisd and intact. The thermal patterns tell how these are connected up the tree.

 

I have made good use of this information in terms of work carried out on veteran beech trees. By being able to see where the wood has near optimal properties, the trees have been pruned and the regrowth has been excelent. Just writing this up for publication at the moment. The best bit is that in many cases the trees could be 'left to their own devices' without any worry about them failing, many with K. deusta as a purely saprophytic growth, others with superficial growths of M. giganteous. Many with Ganoderma sp. This is quite important since I am convinced that many older beech trees go into a kind of transient veteran stage caused by drought from which they recover. The problem is that work is then carried out that accelerates the decline of the trees, where as if they had been left to recover then they would have done so and the only work would be the occasional removal of dead wood.

 

 

Marcus,

 

That's all very good, but I can't help but respectfully say it sounds somewhat "Idealistic".

 

I'm certainly not doubting the science behind TI, moreso the questioning the necessity for it from the customer perspective. I certainly and agreeably concur that there is a vast potential from the research perspective, but as a commercial application........ ?? Highly dubious.

 

 

As some have already put, this NEEDS to be a service that can be "sold" to the end user. As such, it has to provide a either a comparative product at a comparative cost, or be such a level of necessity that can dictate its own value thereby making it commercially viable from the practitioner perspective.

 

Whilst legislation and market forces dictate that easier and cheaper systems of Tree Hazard Assessment are an acceptable means of ticking the "liability box", I really struggle to see why the end customer is going to be willing to pay for a product that just enforces what in 9 out of 10 cases can already be assessed by an expedient and well read Arborist, and will be deemed "good enough" by the resounding industry voice.

[Ian Flatters]

I was thrown on a seminar at barchams and they had some guys from Nottingham uni tech thingy there showing (sales pitch) on thermal cameras. In my opinion i wasn't impressed firstly cost and secondly it kind of stated the obvious?? like a huge cavity and the showed us the lack of heat surrounding it = decay? But we didn't see any photos of bats or bat roosts, which i would imagine would show up clearly at the cavity entrance. But still its the cost of the thing. Would rather save for a picus.....

[Andy Clark]

Yes, but as I understand it the two are independent of one another. Thermal imaging can be used with or without the ‘risk of failure protocol’, and as Marcus has pointed out, it is just as effective it you want to use it to support another risk assessment system of your choice.

 

Throwing the baby out with the bath water springs to mind…… don’t you think.

 

Come on guys, I thought the girls in the clubs were bad at bitching, based on gossip and rumor…..

 

It seams that arborists are far worse.

 

 

 

I'm sorry...... who are you??

[BatiArb]

selection process used to avoid certain areas and or comments......

 

Could you elaborate on this??????

 

I believe a straight question deserves a straight answer.

 

If I do not know something then I will not respond without first checking with someone who does.

[BootyArb]

 

I'm sorry...... who are you??

 

 

Lets just say i am intimately involved......

[Arborist Sites]

Lets just say i am intimately involved......

 

He could be the world famous Sam Corngrass, the man of mystery that no body will talk about......

[BootyArb]

But we didn't see any photos of bats or bat roosts, which i would imagine would show up clearly at the cavity entrance.

 

 

That's because you cannot use it to find roost sites.

 

The technology is not that advanced yet.

[BatiArb]

As some have already put, this NEEDS to be a service that can be "sold" to the end user. As such, it has to provide a either a comparative product at a comparative cost, or be such a level of necessity that can dictate its own value thereby making it commercially viable from the practitioner perspective.

.

 

 

I agree that selling a service is important and finding a place for thermal imaging has been one of the commercial challenges. The fact is that it offers us so much more than other tree assessment tools. It cannot be offered comparably to any other methodology because it looks at different aspects of the trees functional growth form.

 

For a start it presents us with the first proactive means of looking at trees. I have never liked the idea of looking at decay without understanding the functional capacity of the tree and the volume of reactive wood that compensates for the presence of decay. After all, every mature tree will have a volume of decay progressively increasing depending on its physiological health.

 

This technology offers us a completely new insight into tree function and relationship within their growing environment. It provides us with information that no other tool can come close to because we are looking at the positive attributes of the tree and not just measuring the volume of decay.

 

Thermal imaging offers us massive opportunities to learn more about trees and make more informed judgments about their management, because we have a better understanding of their current condition and can compare this to other trees in the same population.

Edited January 12, 2010 by Amelanchier
Continuity - removed first line