[longtime]

I have had one for years. It goes off when the temperature changes(that is normal), It has gone off around Moab, old mines, but never in the dentist office. It sounds a series of peeps to indicate level of radiation. 1 just a little above back ground ( 42 days to get 100 R exp.), 10 run like hell (<2 hours to 100 R. exp.).

 

[longtime]

Mine is the Nukalert