It is not used in our training.
I have no idea where this example came from.
Do you believe everything without verifying it.? I see you are easily led astray.
I know you want to promote your classes, but try to be honest in the process.
SSR better fit in the center 50%
I don’t train John. So no classes to promote.
Back to the original question. Do you know the major flaw in that image and why it should be thrown out. Being an IR trainer you should easily know the answer.
Mr. McKenna,
You wrote"Your talking to all of us like we don’t know anything. Please stop speaking down to us. We are not a stupid as you portray."
My response would be- Do you remember the hoopla we went through with you about the thermal image description you have used in you class for more than 5 years that was WRONG---- you know the one, reflection, paint
You made many comments that we did not know what we were talking about until someone else told you that your description was wrong.
I think the comments that you take issue with are directed at you and not others so don’t use “we” replace with “me”
You sell classes all the time. Don’t pretend not to know that.
You are the one accusing me so the burden of proof is upon you. Teach us oh great one. Try to be honest.
I knew a 13 year old little girl who use to love and play this game. She would say that she knows something you don’t. Can you guess what it is? She would go on and on playing this little game. She needed to feel important.
I am so impressed with you. You know the secret answer and you won’t tell us. You are so special. LOL.
Mr Anderson started out saying all the HVAC and Electrical Specialist in the world are wrong. So his comments triggered in me a response that he is speaking to many and not just one.
Do you have a specific point to make on the subject?
Regarding the error you mentioned, we have all made mistakes. Mr Anderson finally admitted that the error was a “clerical” issue. His words, not mine. At least I correct the mistakes without lying about others to improve my appearance. I did not write the section that needed the minor correction, but I did correct it. Many points over time have been corrected in some of the educational offerings here at InterNACHI. I figure in the future I will make more mistakes, no matter how hard I would love to be perfect. Have you ever corrected a mistake? Did you shut down after that or go on.?
If Mr Anderson says he knows of many examples of others making errors and then post an exaggerated image to illustrate his point… that seems to me that he is speaking to many of us and not just one.
I suggest you go back and read through the thread. Do you have something useful to add? Is your next post going to be an attack or something helpful.
Even if you did not write the section you taught it wrong for a long time and did not see the problem. Glad you corrected it. Jason only asked you to answer if you knew what the problem with the flaw in the image was.
As far as my next response being an attack or something helpful, it depends on what is posted. I prefer to be helpful don’t you?
I’m not sure what this is referring to. Here’s what I read:
Perhaps I didn’t clarify my questions. I am really not questioning the use of Delta T only in the field. I am trying to gauge what the uses are for apparent Delta T and actual Delta T in general. Personally, when I think of using Delta T, I don’t see myself doing calculations or referencing charts in the field. It seems, as Chuck mentioned, with so many materials in just a main panel, one would have to do some work in the office correcting image settings. I was initially wondering what the extent of that work would be. One thing mentioned in some of the coursework was that altering images can make your results less likely to stand up to scrutiny, specifically in court. Does this mean that resetting your equipment settings in the field is the recommended best practice or is editing images later okay for most situations?
I was playing around with Flir Tools and changed some of the emissivity settings on some electrical images. It does make a difference in the final temps as David was mentioning. They can swing 10, 20, 30 degrees pretty quickly depending on the materials. Those numbers appear to be enough of a difference to make an electrical IR image either nothing to consider or a serious defect depending on your settings.
Would I be correct in saying electrical Delta T’s tend to demand more precise measurements than imaging of mechanical equipment?
Is it too far away from the components being measured to get an accurate measurement? Or not centered?
I was waiting for John to answer, but I’ll give it a shot. Distance shouldn’t matter except for the fact that the “spot” is not completely filled with the object being targeted. Camera needs to be a little closer and focused, as this will throw the quantitive values off if not achieved.
Not sure why all the fuss about emissivity as long as you don’t have to compare the metal parts to the plastic parts. Stick with delta T measurements of similar materials and set the camera for the correct E. We are talking an electrical panel, not a printed circuit board.
There is a pretty simple way to get a fairly corrected reading on a low E material without changing the setting on the camera. Does John know what that trick is?
I have no dog in this squabble In my mind I know who is correct and who is incorrect and that is as much as I want into this.
Cameron I will give you a bit of good advice take it or leave it and I have told many newer IR guys this same speech. Take as many electrical/mechanical images as humanly possible with a 320X240 res camera but do Not put any images in a report until you are at least level ll as you will be increasing the possibility of being in court with some level lll explaining to you and the judge how your image produced a incorrect temp creating a undue expense for your client???:shock:
Extremes John?
Are you implying that these emissivities don’t exist in every electrical panel?
Again, this thread is not about you John.Try to focus on the subject matter.
I got this scan from the internet. I changed some things, but as we all should know we can’t change focus, range and distance.
Distance is the problem in the above scan.It is outside the SSR for this camera.
Wow… I thought all those post you made using my name were about me.
How foolish of me… Duhhhh.
Too funny.:mrgreen: You can’t take the moral high ground when your already guilty
of so many attacks and lies about me. Nice try.
OK… back to the question and answer game. David looks so smart,
I am impressed. Ask some more so we can really be dazzled.
Sure they exist. But you are trying to prove that someone is teaching people
to measure things in the panel with wild settings in the camera. Who is
doing this? No one that I know is teaching this.
I won’t try to tell you what you or anyone else should do (other than one should not market or profess to do thermography unless they have real qualifications and know what they are doing), but I will tell you what I do.
On small jobs like a residential panel inspection, I will typically leave my imager ε set to 1.00 and focus more on the patterns than absolute temps. I can usually recognize the pattern typical of a loose or high resistance connection vs a heavily loaded conductor or breaker. If I see an anomaly, I will always attempt to get an amperage reading to validate / support my observation and to better understand the potential immediacy of the issue (e.g., small deltas under small loads can equal very high deltas under higher loads). I never inspect panels without the ability to take load readings. I try to stick with higher ε value targets over lower ε value (I really want to be focused on things that are going to be .9 an up).
I always try to compare a component to a similar component under similar load. The ideal scenario is to compare different points on the same circuit to itself (e.g., the line side of a fuse or disconnect to the load side) because the load will always be the same. I also want to compare similar materials to similar materials because my imager is not capable of assigning different ε values to different targets within the same image (although I’m capable of comparing materials with dissimilar ε values, it’s simpler and more accurate to compare similar ε targets - so don’t try to compare the shiny terminal to a breaker body). Only if I cannot do a like to like comparison will I resort to an ambient comparison inside of an electrical panel. Because, I’m focusing with high ε targets at close proximity I don’t typically futz with imager settings (we’re talking residential type inspections). The difference between an ε of .95 vs .90 will not yield a significant difference in this application. Once I’ve determined that I’m going to treat a thermal anomaly as an exception I will use the NETA maintenance test scale to assign a priority classification based on Delta T. (more often than not I’m using apparent)
In an industrial setting, my method is different. My largest commercial electrical inspection last year resulted in an 800+ page report. It involved voltages up to 13.8kv, 480v breakers up in in the 2500Amp range and step down transformers at 5,000kvA. Every time I moved to a new area or changed the distance from the target, I checked and set RAT, AT, humidity and distance parameters in the imager. When appropriate, I also reset the ε value. However, the nature of most of what we were shooting precludes you from being able to actually test the ε value of your subjects (so we focus on high ε targets and shoot in such a way to maximize the effective emissivity)
I went back last week to re image about a dozen 13.8kv sectionalizers and eight 5,000kva transformers. One of the sectionalizers had experienced a failure and I was able to retrieve a piece of the insulative covering from the failed component to perform an emissivity test on it. Turns out the actual emissivity of the material was… .95!
My advice is: Know your capabilities and stay within them. Know what your application demands and apply the appropriate level of rigor based on the situation. Be deliberate, not careless in your decisions about how critical your measurements are. Control variables because mistakes in your assumptions can have a compounding detrimental effect on accuracy.
BTW - a word about spot size ratios and imager target reticles: There is no guarantee that the target reticle on your imager display actually represents the real spot size for your imager (especially with lower resolution imagers) or that the actual location of the spot being measured corresponds to the location depicted by the reticle. Be conservative regarding your spot size when performing quantitative analysis.
Okay there is something I don’t understand. This argument which is going on about emissivity settings and infrared imagers compared to infrared thermometers seems very elementary.
John brought up infrared thermometers being used by HVAC and electrical contractors. If the IR thermometers have a fixed emissivity setting of somewhere around .9 and they are used to measure newer copper wire, which is around .02-.05, wouldn’t that produce a major error in the temperature readings compared to using an infrared camera or software with exact emissivity settings?
And if it were used to measure oxidized copper, which is somewhere around .6-.8, wouldn’t this still produce a significant error of many degrees?
As Mr Evans stated… with an IR camera on residential panels, stay with high e materials. I would advise the same if using a IR thermometer.
Both are measuring temperature with an IR detector(s).
You are correct in your statements.
John, how long were you doing IR before you started teaching? How many specific inspections did you complete and at what level of certification did you attain and from what organization? I am just curious. Thanks
I helped put together the first Infrared Certified class material with another more experienced IR thermographer named Will Decker. He held the initial class and I did not teach my first class until I had one year’s experience. I took the building science class and was certified as a building science thermogrpher by ITC, which is the training arm of FLIR. They have since renamed the class but that is how I got my first training and certification. That was 7 years ago. I did approx 170 inspections with IR in my first year. I have been a TREC home inspector for 15 years and before that I had about 25 years in construction. I was a general contractor. Our IR class is an entry level course for home inspectors. We get a lot of energy audit and contractors take our class as well. Nick Gromicko ask me to be InterNACH’s IR instructor at time. Very few were doing IR back then. I helped Nick put together several videos for IR and have been teaching ever since.
No offense John, but how would you know what material to include in an IR class if you had yet to complete training and had no field experience at that time? Then, you completed the training you helped to create and started doing IR inspections. Do you see an issue with that? Do you inform your potential students of these facts?
I’m sorry that I confused you. I got trained (ITC) and then did 170 IR inspection in the first year after training. Then I began teaching after that. Just before I started teaching, and after I was teaching for a while, I helped to develop InterNACHI’s IR course material and did some videos.
Does that make it more clear now?