The S.E.M. (Simple Energy Meter) is a device that produces 3 different tones to detect EMF, Ionization, and Static changes in the environment. The higher the tone emitted the stronger the changes in the environment. How the SEM works:When turned on the SEM indictor will glow and change intensity. When the field around the SEM changes, the SEM will produce a tone based on the level of energy change. The higher pitched the tone, the greater the energy change.How do I use it? Place the SEM in an area where you"re monitoring "activity." Turn them SEM unit on and move away. The SEM may produce tones for a few moments as it adjusts to the area, then it will go quiet.If triggered the SEM will produce 3 different tones the higher the pitch of the tone the greater the energy change. The SEM is sensitive to EMF, Ionization and Static charges.Testing: After the SEM has been running for a few minutes and becomes quiet, touch the SEM with your hand; the SEM should now give off alert tones.