WAGO 758-915 Manual

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WAGO 758-915 Manual Manual pdf 71 page image

WAGO-I/O-SYSTEM 758 Appendix 71758-915 Bluetooth ® ETHERNET GatewayManualVersion 1.1.0, applicable from FW/HW Version 01/018.7 Health ConsiderationsThe device emits microwave radiation. It is explained in the safety instructionsthat the device is not meant to be directly operated while in contact with thehuman body. As with any other type of radio waves, there is a certain degree ofinteraction between microwave radiation and human tissue. The intensity of thisradiation in the frequency range used by the device is, however, the decisivefactor in determining whether these effects can be measured or whether they mayeven be harmful.Despite their related frequency ranges, communication devices are in no waycomparable to microwave ovens, which operate at a considerably higher powerlevel (600 W and higher) and concentrate their energy into a tightly enclosedcompartment in order to achieve the best effect.Radio communications devices, which are allowed to communicate license-freethroughout the world in the ISM band at around 2.45 GHz are, on the other hand,subject to legal provisions restricting their transmitting power to 20 dBm EIRP(“equivalent isotropic radiated power”), which corresponds to an output of100 mW = 0.1 W.Commercially available cell phones, which are carried close to the body or heldup to the ear, operate at frequencies up to 1.95 GHz and may only have atransmitting power of up to 2 W EIRP. In-car phones and other similar deviceswhich are not carried on the body may even have a transmitting power of up to8 W. These values exceed the maximum, permissible transmitting power forBluetooth ® technology in the ISM band by a factor of 20 or 80.The distance to the antenna must also be taken into account here. At a distance ofmerely one meter the field strength already drops by 40 dB, which corresponds toa factor of 100.Therefore, based on current knowledge the following can be said:When used properly, the risk of hazards or injury to humans by radio waves usedin Bluetooth® technology can be ruled out.