Both of my Level I and II certifications were taken at The Infraspection Institute. Once you have attended the required 32 hours of instruction and passed the final exam, you are awarded the certification level. After that, there are no further requirements.
Kevin, I was awaiting your completion to get the scoop. Not picking on the provider, just want to know for me.
ITC requires class attendance, two quizzes, a final and a field exercise to be completed in 90 days. All are weighted as to final certification. (just for any one’s info.)
It is up to the individual graduate to advance his/her career and experience through various means, such as on the job training, work experience, continuing education, etc.
ITC requires CEU’s in two years to remain certified. This can be through the next Level, other related training, or writing a paper to be published.
I’m not sure I follow the logic of waiting two full years to take the Level II course. I’m not against the idea, just do not understand the logic. Level II expands on the theory learned in Level I and then takes it a step further and includes “accurate” temperature measurement. After taking the Level II class, I know how to calculate reflectance, emittance, and transmittance in order to take “accurate” tempertaure measurements. I also was taught how to “calibrate” my own camera.
The “up to two years” experience is to use the next Level Class to remain certified. For those working for a company, this may coincide with employment advancement. They suggest this additional experience (not require it) before taking the next level to learn by doing. As I said before, the 2 yrs I have under Level I will end when you are certified Level II.
Level II is not rocket science, but it was no walk in the park either. It cover advanced IR theory, physics, algebraic calculations, and temperature conversions. It was very challenging!
I’m waiting to hear from Charlie B when he finishes Level II.
You posted that Level I was qualitative and Level II was quantitative. I found ITC BS qualitative and Level I Quantitative (though not as advanced as Level II is likely to be). I don’t even remember anything about “Qualitative” in Level I. We had the high power switch gear guys in class and they work off of exact temps. One thing I noticed in Level I was that there was about $600k more camera in class than in BS.
I thought it was more beneficial for me to take the Level II soon after the Level I so that the theory was still fresh in my mind. Whatever works for you 
I felt I had time to let things sink in and do after course study. Things that were not fully covered in BS left many questions which I felt working up the Levels would (and is) answering.
Kevin