Principles and Methods of EMF Safety Maintenance by Individual Protective Means

摘要

According the electromagnetic safety principles one of way of this solution is protective mean use. There are 2 main kinds of protective means: collective and individual. Collective protective means in dependence of EMF frequency range decrease EMF value by means of EMF reflection or absorption. Individual protective means (protective suits) use as a rule in cases of static electric field, power frequency (50/60 Hz) electric field and radiofrequency (RF) EMF occupational exposure. The methods of these protective suits testing arc developed in different countries. Great difficulties are connected with correct evaluation of RF EMF individual protective means protective characteristics. There is presented the method of RF EMF protective suit (PS) safety properties evaluation. Safety properties of modern PS arc based on EMF reflection, which ensures shielding effect. PS is made of electro-conductive materials; all elements are connected to produce a "cover" around a human body, which allows reducing the EMF values to permissible levels. The testing of protective suit is carried out by special setup use. EMF is emitted by means of RF generator connected with antenna through amplifier. Special setup includes human body phantom (head, trunk and extremities) and measuring probe connected to personal computer by optic fiber. Phantom is placed in spatially homogeneous EMF for all body parts. EMF measurement is carried out in three control points (head, breast and groin) at fixed distances from RF EMF source in two phantom positions: in front and back to the RF EMF source (with and without PS). The results obtained by suggested approach allow determining PS protection level (in dB), and develop recommendations for construction upgrade. Furthermore, the obtained data of shielding effectiveness suggest that there is the relationship between protective properties and RF EMF values. Proposed method of PS shielding effectiveness evaluation can help analyze that relationship in future studies.