Nashville, TN – welcome to day 1 of Snell’s Infrared Thermography Level II class. One of the nice things about Snell’s system is that class doesn’t get started until 3 PM for the first day allowing for those of us travelling, time to get to the hotel & settled in. It also eliminates the issues with an entire morning being wasted with registration, waiting for people to find the location, etc… Unlike my last class with Snell for Level 1 with by Don Thurmond & Jim Fritz (great instructors & class – wish I would have thought about writing about these classes back then) this one is being taught by just 1 instructor named Harold Van De Ven aka Van. This class also is smaller with 13 of us coming from all parts of the US. If today is any hint of things to come, Snell has a way of picking great instructors.
IR Levels & Certifications?
There are 3 Levels in the IR/NDT fields (IR = Infrared /NDT =Non Destructive Testing) which falls under the ASNT SNT_TC_1A. Part of the confusing aspects faced by many is that the ASNT only certifies individuals for Level 3, but allows for employers to certify individuals in their own companies up to & including Level 3. The catch for many individuals is if they leave a company, they automatically loose there certification unless it was done by the ASNT. Now said individual can go to future employers & show that they have met the training requirements recommended, and have done X amount of hours, but it is up to that new company to decide if they wish to accept that or require more time &/or training.
Per the ASTN their guidelines are similar for a Level 1 & 2 Thermographer which includes 32 hours of approved classroom teaching, a practical exam, a 40 question General Written Exam, followed up by a 20 question Area Specific Exam (Buildings, Electric, Motors). To get a passing grade, you must get a 70% or better on each of those tests, with a minimum 75% overall. Where the two differ is in the hours behind the camera or the desk analyzing & doing reports which is 210 hours for Level 1’s and 1260 hours for Level 2’s. In the words of our instructor a Level 1equates to one with a learner’s permit, while a Level 2 is equivalent to an experienced CDL driver. As for the Level 3… well that equates to the suit behind the desk aka the Administrator.
The next 4 days & some Trivia for you:
The next 4 days (minus the testing portion) is mainly on how to get an accurate temperature when it is required and the steps to do so (as he forewarned us, it is about a 15 minute procedure). We will also be diving a little more into subjects like quantitative approach, thermal capacitance, the 5 types of heat transfer, mid & long wave cameras, pulse thermography, immersion & surface temperatures, and how to determine you & your cameras IFOV (Individual Field of View). This ought to be fun & let me leave you with just 2 easy pieces of trivia – 1) when should you expect to see & not see a Zebra’s stripe’s in IR, and 2) what makes a thermos so effective (i.e. how do they keep items so hot or cold with NO insulation – 3 part answer). Feel free to leave your answer in the comments section, and look for the answers in a future article.
The Picture – Union Station in Nashville, taken from the hotel I am staying at. As there are many more great buildings around, I can hopefully sneak in a few pics of them & just maybe 1 or 2 of that one in Infrared.
1) I would expect to see the zebra’s stripes in day light, when the zebra’s darkly striped skin is absorbing more solar energy and is slightly warmer than the lighter striped skin. I would expect to not see the zebra’s stripes at night when the animal’s skin is all of uniform temperature.
2) Ah..did you know the Thermos company is headquartered in Norwich, Connecticut? The Thermos is double walled and there is a vacuum between the inner and outer walls. The absence of air (or anything else for that matter) between the walls means no conductive heat loss. Since the thermos is a sealed/closed container, there cannot be any convective heat loss. And a reflective lining prevents heat loss due to radiation. But no thermos is perfect, and I would speculate that the weak link is often in the cap. If not designed right, the cap is a conductive thermal bridge, although it is a small area compared to the rest of the surface area of the flask itself, so probably not quite that critical.
There…where do I go to collect my prize??? 🙂
Oh yeah..and where the inner and outer walls join together is also a thermal bridge, but a small area, nonetheless…. 🙂 #AttentionToDetail
No I did not know that about the headquarters & you almost got it nailed perfectly – no convective losses due to vacuum / no air; no conductive loss with the exception of the small rubber gasket at the top where the two parts are sealed (and the lid), and perfect on the radiation & zebra
For the last Level 1, 2, 3 question – As the owner of the company I could say I am a Level 3 if I so choose to or anoint someone else if I choose to – the ASNT standards are basically just recommendations for companies so that is major buyer beware situation. I am going to dig into that probably more in a month or two.
So I have a question for you regarding ASNT and certification. You stated in your post that the employer certifies an employee for Levels 1 & 2: If you’re self-employed, how exactly does that work? How is an owner/operator certified for Levels 1 & 2 after completing the training? Do they just self-certify?
As the owner of a company, I could simply say I am a Level 3 if I so choose to or anoint someone else if I choose to – the ASNT standards are basically just recommendations for companies so that is a major buyer beware situation. I am going to dig into that probably more in a month or two.
1) I would expect to see the zebra’s stripes in day light, when the zebra’s darkly striped skin is absorbing more solar energy and is slightly warmer than the lighter striped skin. I would expect to not see the zebra’s stripes at night when the animal’s skin is all of uniform temperature.
2) Ah..did you know the Thermos company is headquartered in Norwich, Connecticut? The Thermos is double walled and there is a vacuum between the inner and outer walls. The absence of air (or anything else for that matter) between the walls means no conductive heat loss. Since the thermos is a sealed/closed container, there cannot be any convective heat loss. And a reflective lining prevents heat loss due to radiation. But no thermos is perfect, and I would speculate that the weak link is often in the cap. If not designed right, the cap is a conductive thermal bridge, although it is a small area compared to the rest of the surface area of the flask itself, so probably not quite that critical.
There…where do I go to collect my prize??? 🙂
Oh yeah..and where the inner and outer walls join together is also a thermal bridge, but a small area, nonetheless…. 🙂 #AttentionToDetail
No I did not know that about the headquarters & you almost got it nailed perfectly – no convective losses due to vacuum / no air; no conductive loss with the exception of the small rubber gasket at the top where the two parts are sealed (and the lid), and perfect on the radiation & zebra
For the last Level 1, 2, 3 question – As the owner of the company I could say I am a Level 3 if I so choose to or anoint someone else if I choose to - the ASNT standards are basically just recommendations for companies so that is major buyer beware situation. I am going to dig into that probably more in a month or two.
So I have a question for you regarding ASNT and certification. You stated in your post that the employer certifies an employee for Levels 1 & 2: If you’re self-employed, how exactly does that work? How is an owner/operator certified for Levels 1 & 2 after completing the training? Do they just self-certify?
As the owner of a company, I could simply say I am a Level 3 if I so choose to or anoint someone else if I choose to – the ASNT standards are basically just recommendations for companies so that is a major buyer beware situation. I am going to dig into that probably more in a month or two.