CalAmp Guardian-100 User Manual

CalAmp Guardian-100 User Manual Manual pdf 23 page image

001-5006-000_FCC.docx Page 23Table 2.2 – RF Exposure Compliance Minimum Safety DistancesAntenna Gain5 dBi 10 dBi 15 dBiMin Safety Distance(VHF @ max power) 123cm 218.8cm 389cmMin Safety Distance(UHF @ max power) 105.7cm 188cm 334.4cmMin Safety Distance(900 MHz @ max power) 63.8cm 115 cm 201.7 cmNote: It is the responsibility of the user to guarantee compliance with the FCCMPE regulations when operating this device in a way other than described above.The Guardian radio uses a low power radio frequency transmitter. The concentrated energyfrom an antenna may pose a health hazard. People should not be in frontof the antenna when the transmitter is operating.The installer of this equipment must ensure the antenna is located or pointed such that itdoes not emit an RF field in excess of Health Canada limits for the general population.Recommended safety guidelines for the human exposure to radio frequency electromagneticenergy are contained in the Canadian Safety Code 6 (available from Health Canada) and theFederal Communications Commission (FCC) Bulletin 65.Any changes or modifications not expressly approved by the party responsible forcompliance (in the country where used) could void the user's authority to operate theequipment.2.6 TERRAIN AND SIGNAL STRENGTHA line of sight path between stations is highly desirable and provides the most reliablecommunications link in all cases. A line of sight path can often be achieved by mountingeach station antenna on a tower or other elevated structure that raises it high enough toclear surrounding terrain and other obstructions.The requirement for a clear transmission path depends on the distance to be covered by thesystem. If the system is to cover a limited distance, say 3-5 miles, then some obstructionsin the transmission path may be tolerable. For longer-range systems, any obstruction couldcompromise the performance of the system, or block transmission entirely.The signal strength (RSSI) at the receiver must exceed the receiver sensitivity by anamount known as the fade margin to provide reliable operation under various conditions.Fade margin (expressed in dB) is the maximum tolerable reduction in received signalstrength, which still provides an acceptable signal quality. This compensates for reducedsignal strength due to multi-path, slight antenna movement or changing atmosphericlosses. CalAmp recommends a 30 dB fade margin for most projects. Table 2.3 shows theRSSI versus Reliability.RF Exposure