Yo homie, let me axe you sumthin, you know bout dat CDD?
If ignorance is on display here, it's mine of coronal discharge detectors as I don't really work with them (I think we disagree on controlled demolition for 9/11, long time since we've gotten into it though, thinking years). I usually stick with photoionization technology for refrigerants with a low enough ionization potential (excepting Ammonia), or infrared when it's available, but when I'm involved we're usually looking at quantifying the amount present at the ppm level moreso than just detecting that a leak has occurred. There IS a really cool one I read about from their patent filing here: http://www.google.com/patents/US20120047926.
I'm not sure how pleased I am with the HF floating around though, I'm not sure if the sensing element, which I'm assuming is electrochemical, is capable of metabolizing all of it or if some of it would float free into the air which.... doesn't sound fun.