That answer is kinda long, I know I'm a few months past when you asked it, and if you came to a answer aready then you could probably disregard. NaI crystal is in my experience more sensitive per size, although comes with quite a few issues. Most notably its sensitivity to moisture and shock. Plastics dont have this issue but you will still need to worry about shock hazards with your photomultiplier tube. With plastic you also have to consider type same as a crystal scintillator. On average your most common types are either BC408 or BC412. BC408 plastic will detect across the range radiation primarily beta & gamma, but also alpha and xrays if probe allows. While BC412 will detect mostly gamma & Xray radiation, and because of this is more sensitive to those radiations. For comparison in size a 3in diameter by 1in BC412 scintillator in my natural back ground will settle at around 3kcpm while a 1x1x2in NaI will average about 5kcpm. Both react quite well across the range to different isotopes that will be commonly a hazard in scrap metal industries, just the NaI produces more counts being the crystal is harder to radiation. Producing more stoping ability. Ultimately there quite a bit to factor, I would personally recommend a plastic scintillation material for use in industrial environments, where surveyors will be moving about. Any plastic scintillator will be sensitive, for plastic size does matter. I'd suggest a 2-3 inch size. With a thickness of 1-2 inches. Such as the one shown. Quick note plastic can sometimes over respond to a source, but other scintillators can as well. Where energy response the meter sees is not proportional to the energy of the radiation. Hope that helped alittle. -James.

@@jamesluck2969 That helped a ton thank you so much for answering. Even though it’s been about six months, Your information is extremely useful and the advice from someone knowledgeable is worth a lot to me! I really appreciate it. I ended up with a few used but calibrated Ludlum meters and ended up experimenting with both plastic probes that I built DIY in my lab… And some really nice Nai(tl) probes purchased slowly online as they appeared at good prices. Really enjoying getting more and more into this hobby. It’s really a golden age of technology… A lot of really nice decommissioned equipment can be found for pennies on the dollar online. I’v stumbled across and purchased all kinds of awesome Radiation monitoring equipment from airports and government stuff....all types of interesting and crazy things!!!

Pay attention to the entire video. I picked a weak signal on purpose. It was fading as HF is wont to do. You're free to make your own video...

Well aren't you pleasant? Did you not comprehend that the name of the road I was on was "Norma Rd"? I wasn't IN Norma, I was ON Norma. That's the New river on the left. I took 116 to New River Road, Stony Fork, Shea, Norma to 297. Look at a damned map

+Ryan Indeed it was! We grabbed pizza there at Carota's before heading down to Morehead.

Yup