cookies4life - I checked to see what this model claims to do. The literature seems vague about what kinds of EMF can be detected, but even the Home Depot description lists the concerns about cell phone emissions. Most of these DIY EMF sensors seem to be manufactured and sold for detecting poor gasket or shielding issues around microwave ovens, potentially very high powered sources of radiation in the 2.45 GHz spectrum (a frequency not used by cellular phones, but close to frequencies used by many cordless phones). So there is a question if these detectors are capable of operating effectively in testing cell phone emissions. If you look at over 70 customer reviews of this model at the Amazon.com site, many buyers found it impossible to detect cell phone signals, but it readily sensed microwave oven radiation.
There is a Science Buddies project on this subject at -
http://www.sciencebuddies.org/science-f ... ml#summary. If you haven't reviewed it, perhaps some of their tips and techniques for measurement may help. I don't have any personal experience with this project, so can't directly help beyond this. By the way, you should note that to operate at all, every cell phone must emit RF radiation. Is it all dangerous? What levels have been noted in other studies to be potentially dangerous to human tissue. There is a lot of research you can do to better understand the entire subject.
Rick Marz