Dear Sellan There are key four frequency band used in RFID. LF (Low Frequency), HF(High Frequency), UHF (Ultra High Frequency) and Microwave 2.45 GHz. As requested by you benefits of HF and UHF is described: 1) High Frequency (HF) 13.56 MHz. HF is widely deployed. It is minimally affected by moisture and uses higher data transmission rates than LF. Read range is below 1.5 meters. Manufacture of HF tags can be achieved using very low-cost, reel-to-reel processing techniques, offering low-cost tags. The frequency is highly reliable and predicable in the presence of metals and for random tag orientations. Main applications are for asset tracking applications, such as library automation; laundry process automation; courier- and item-level supply chain; and retail tagging applications. This is approved frequency for libraries by the standards organisations such as ISO and NISO. 2) Ultra High Frequency (UHF) 860 - 960 MHz. UHF is less globally harmonized for frequency and power regulations than LF and HF, although initiatives by EPCglobal have improved this situation. Currently, different countries have different UHF frequencies available for RFID, and different power levels available. The UHF frequency offers greater read range than other frequencies, but is adversely affected by moisture and cannot read tags shielded by the human body. The presence of metal also creates reflective surfaces that can dramatically degrade the performance of these systems. UHF antennas are tuned to receive RFID waves of a certain length from a reader, just as the tuner on the radio in a car changes the antenna to receive signals of different frequencies. When UHF antennas are close to metal or metallic material, the antennas can be detuned, resulting in poor performance. The main applications for UHF are pallet and case tracking for supply chain logistics and vehicle tracking; however, some item-level applications are being implemented and industry groups are considering additional applications. Few experiments have been done in the area of UHF by the China in collaboration with Hong Kong libraries and they are treated as founding member of the UHF RFID in library. Hope this will help you in choosing the best. Rajesh Chandrakar First Ray Consulting -Single Stop Solution for Library www.firstray.in On Friday, July 18, 2014 5:52 PM, "SAIACS, Chief Librarian" <library@saiacs.org> wrote: Dear Colleagues, It is to seek your insights and valuable information on use of UHF RFID tags for library security system. We would like to know whether or not use of UHF will be harmful to human bodies? Are There Any Health Risks With Prolonged Exposure to UHF? We are in the process of identifying suitable technology (HF or UHF) for our library, your inputs will help us to make right choice. Should we consider using HF over UHF?? Please share your experiences and opinions in this regard. Thanks Yesan Sellan, B.Com., MLISc., PGDLAN, UGC-NET., BCS Chief Librarian South Asia Institute of Advanced Christian Studies (SAIACS) 363 Dodda Gubbi Cross Road, Kothanur P.O., Bangalore 77, India Phone: 91 80 2846 5235/5344/ 5649, Fax: 91 80 28465412, Mobile: 91-9972348251 Website: <http://www.saiacs.org/> www.saiacs.org Alternative Email: <mailto:yesans@gmail.com> yesans@gmail.com or <mailto:yesan.sellan@saiacs.org> yesan.sellan@saiacs.org ______________________________________ IMPORTANT : This message is intended only for the addressee. It may contain confidential information. Any unauthorized disclosure is strictly prohibited. If you have received this message in error, please notify us immediately so that we may correct our internal records. Please then delete the original message. Thank you. P Please consider the environment before printing this email. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.