This is a clever device that shows whether the Deta-Elis AP and Ritm devices are indeed working with proper limits. It basically illustrates the intensity and the quality of the electromagnetic spectrums emitted by these devices. The Deta-Test simply tells the owner of the Deta-Elis devices whether they are working or not and whether they are in need of repair or a service. The operation mode of the Deta-Test is simplicity in itself. Simply turn the Deta-Test on while also turning on your AP or Ritm device – the Deta-Test automatically picks up the device and shows a light on the panel. There are three indicator lights: Green light: the appliance is working normally Yellow light: not enough power (the battery needs changing in the control device) Red light: the device is not working and needs repair.