Will this example work?

Using my IR camera, If I were looking at an interior ceiling for a possible water intrusion.

Could I simply dip my finger in the kitchen sink then smear it on the ceiling?

I could then set my span within the correct temperature I’m looking for.
If there was a moisture intrusion in the ceiling it should fall somewhere between the actual ceiling temperature and the water I smeared. Making this signature easier to locate.

Your thoughts…?

You might be happier if you take a good IR upgrade course .

It’s actually not that simple… Have you trained on it? Much to know, many variables to be aware of.

Thanks Roy but you didn’t answer my question.

Thanks Jamin but you didn’t answer my question.

It works better if you overflow the second floor tub, wait 20 minutes and then use that section of ceiling as your reference. Gives you something dramatic to show off to the client too.

made me pee my pants…:smiley:

now give me your expert advise…

The reality is that the question borders on the hysterical. Hopefully, most readers will assume that you are being facetious.

The short answer is that its a really bad idea. It’s ill-conceived and completely unnecessary.

Conduct your own experiment Jim and let us know the results.

Keep in mind though (against what many are taught) not all moisture intrusion will appear as a dark/cool thermal exception… and under some (very commonly encountered) conditions will be completely hidden in the infrared spectrum even when it is plainly visible to the naked eye. The latter will likely be encountered more with lower end / “entry” level equipment.

Place a drop of tap water on your kitchen counter and see how long it takes to become “thermally invisible” if it does at all.
Do the same with a drop of hot water.

Perform the same tests in an unconditioned basement on the slab floor.

Perform the same tests in a heated bathroom with exhaust fan off… then again with it on.

Make sure to capture images at regular intervals for comparison.

Now do all of the above but place the drops on an absorbent material.

It literally is an eye opener in each setting. Experiencing the results first hand is the best way to learn.

Complete understanding and comprehension of thermodynamics and evaporative cooling as it relates to thermal imaging under various real world applications is vitally important for accurate use of infrared technology in a residential application.

Here’s the problem I’m running into:

Some infrared cameras do not have the ability to manually adjust the Level and Span, which is the equivalent of brightness and contrast. This can often be accomplished with image processing software after the image has been captured and saved. However, anomalies can go undetected in the field if the level and span are not adjusted well. If no problem is detected in the field, the image will probably not be saved for further analysis.

My goal is to add another IR course this year, but until then I’m asking my experienced IR NACHI members for a little help and guidance.

The reasoning behind this was when on another thread, I was told to place a piece of black tape on the reflective object to get the correct reading.

And yes, it’s easy to be ignorantly hysterical! I remember the day two older carpenters told me to go get the board stretcher. And I went looking.:wink:

OK got it. I would suggest avoiding imagers that do not have adjustable focus or span controls.

In either case, control your environment to improve your chances of detecting moisture. The process you you want to be concerned with (for now anyway) is evaporation. Evaporation is endothermic (it absorbs heat) making the wet area cooler (like sweating on a hot dry day). The more rapid the rate of evaporation, the greater the temperature difference will be. To enhance evaporation, decrease humidity, raise temperatures and move air.

Experiment at home as Bill suggests. Be aware that some materials enhance evaporation, while others impede it. MDF trim can be very difficult to detect moisture in.

Always, always, always verify suspect areas visually or with a moisture meter.

The electrical tape is used to achieve a known emissivity for temperature calculation. You aren’t concerned with actual temperatures, only temperature patterns (i.e., qualitative) when looking for moisture. You can completely ignore emissivity (I recommend setting it to 1.00 and forgetting it for this).

Yep!

We’ve preached to the masses more than once… the cheapest of equipment and training does not a building thermographer make… no matter how experienced a building inspector one may be.

On the same token we certainly understand budget constraints… but buyer’s remorse is still harsh to deal with even for one of the cheapest cameras available.

Hopefully at least your imager auto spans… again you must experiment on your own. Avoid high and low temp objects as best you can in the field of view such as lights, cold pipes, reflections of the same, etc. Practice makes perfect and start saving your coin and doing research for a camera better suited to your application needs. Not just one the vendor said would work or everyone is buying.

A note on inexpensive imagers:

My advice is that if you need an inexpensive imager to start out, you may well be better off purchasing a good, capable second hand imager from a reliable source over a cheap new imager. John M. disagrees with me, which reinforces my thinking on this.

My personal policy on buying second hand imagers is to start out at no more than 50% of new pricing for the unit being considered.

wwarner;991288]Conduct your own experiment Jim and let us know the results.

Keep in mind though (against what many are taught) not all moisture intrusion will appear as a dark/cool thermal exception… and under some (very commonly encountered) conditions will be completely hidden in the infrared spectrum even when it is plainly visible to the naked eye. The latter will likely be encountered more with lower end / “entry” level equipment. I’m seeing this more during cold weather.

Place a drop of tap water on your kitchen counter and see how long it takes to become “thermally invisible” if it does at all. Immediately.
Do the same with a drop of hot water. Immediately.

Perform the same tests in an unconditioned basement on the slab floor. Not available tonight.

Perform the same tests in a heated bathroom with exhaust fan off… then again with it on. Done.

Make sure to capture images at regular intervals for comparison. Done.

Now do all of the above but place the drops on an absorbent material. I used a white dry washcloth, cotton.

It literally is an eye opener in each setting. Experiencing the results first hand is the best way to learn. Sorry but the only eye opening experience was my wife, because apparently I used one of the Good washcloths for my experiments.:frowning:

I saw the heat differentials and with the absorbent material, it was just spread out further.

Complete understanding and comprehension of thermodynamics and evaporative cooling as it relates to thermal imaging under various real world applications is vitally important for accurate use of infrared technology in a residential application.

This past summer, turn on the ac, scan the house, then verify with my moisture meter, no problems.

Now that winter is here, all kinds of problems. Even though the Delta T is sufficient, I find myself climbing up and down the ladder a lot to verify with my moisture meter, and it turns out to be fine…getting tired of all the extra climbing.

Like you stated “and under some (very commonly encountered) conditions will be completely hidden in the infrared spectrum even when it is plainly visible to the naked eye”. I seen this two days ago on a bathroom floor. I seen it with my eyes, but the ir camera didn’t.

Again my goals will be in baby steps this year, so one class, and maybe an ir camera upgrade around $4000.

I do appreciate the help and advise.

Disturbed loose fill insulation can be quite deceiving during this time of year. :wink:

Especially if you can’t manually adjust your span.

I’ve owned this new flir i7 for almost two years now. Along with John’s $500 course and NACHI’s course.

Yes, I can adjust the span, and I was trying to “think out of the box” with my initial post (which got quickly shoved up my A hole):).

I know my tool and education is like a barber stepping in for a carpenter to cut a piece of trim with a chain saw.

My ir camera is a tool like my moisture meter, and I’ve not had one customer complain about the results. But, then again, I only set their expectations to just above my knee.:wink:

But all joking aside, If the temperature of the ceiling and moisture on said ceiling, has the same temperature, would it be the reflective temperature that I’m looking for? OR The pattern from the reflective temperature? to distinguish the two.

The answer to your question is in your question… if they are in thermal equilibrium there will be no measurable temperature difference and no thermal exception detected.

If they were not in equilibrium it would be the emitted energy and resulting pattern in the material you are trying to detect.

I apologize, I really got lazy. I should have read my own study material before I asked that question.

Thanks for the intelligent response. And, by the way, I visited your web site to see where you took your studies, but didn’t see any reference, did I miss it?
Just trying to research my next step in the ir education.