There are a few ways to tell if your device is working. Qi-devices release negative ions into the air, one of the easiest ways to is use a negative ion meter for the air. You can also do a before and after organic acid test, looking at ATP production and mitochondrial function. The third way is a before and after brain scan.
Many people are EMF sensitive and can feel EMF emitters such as WiFi routers. When a Qi device is introduced, these EMF sensitive people can no longer tell if a WiFi router is on or off. We often hear our customers tell us that their Qi devices lead to improved sleep and decreased EMF pain and headaches.