http://www.emfnews.org/

Measurement of the emissions from cell towers presents particular technical challenges beyond those encountered for broadcast antenna sites. To understand these challenges, a few comments about radio frequency measurement are required.
Protocols for the measurement of RF energy for the purpose of human exposure assessment often recommend the use of an "isotropic broadband probe" because this type of sensor responds equally to energy arriving from any direction, and over a broad frequency range, as does the human body. These instruments are commonly used because they permit a quick and simple measurement. Unfortunately, some of the meters used for typical RF compliance surveys are unable to accurately measure the low power densities present at some cell sites. An alternate approach is required.

http://www.emfnews.org/store/
http://www.emfnews.org/products.html