The Gauss Master EMF meter works very well. It has 2 settings for sensitivity, 1-10 milligauss and .01-1 milligauss. The meter has an audio alert that reacts to the amount of energy being measured. The meter is very easy to read and light weight. CCPRS uses this unit as a hand-held device during investigations. The only draw back to this device is that there is no real on/off switch. The button on the side turns the unit on and when depressed changes the unit of measurement to the more sensitive setting.  If the unit idles, or doesn't detect anything after a short period of time it will automatically shut off. This is something that you must be aware of when using this device, otherwise the unit can shut off during an investigation and a missed opportunity could be had. This device is inexpensive and can be found on the web for $35-50.00 USD.