Interesting take Randy. This is and has always been the standard in Illinois. Only licensed measurement technicians / professionals may place or retrieve test devices.

I am continually baffled why "radon professionals" continue to utilize antiquated equipment which does not measure background / environmental data. This is a key component to determining interference or tampering! I just don't get it. I'm not here to bash the 1027. It has certainly proven itself as a dependable workhorse. But Sun does make better monitors for real estate testing, along with countless other manufacturers! Higher sensitivity = More accurate results, and tamper detection built-in, all for a reasonable cost.

PS -I would not care if my employer did not require a NIA, I would make sure to get one anyway!

Bruce is correct. The Tyvek is simply a diffusion barrier. Rn levels will not be skewed by using Tyvek bags, IMO. I was curious several years ago and did some side by side studies (with bags and without) and they were all spot on.

Here in Illinois, testers are prohibited from mitigating. Hoorah for licensing!!