Detail of YD/T 1644.2-2011

Introduction of YD/T 1644.2-2011

Human exposure to radio frequency fields from hand-held and body-mounted wireless communication devices— Human models, instrumentation, and procedures— Part 2: Procedure to determine the specific absorption rate (SAR) for wireless communication devices used in close proximity to the human body (frequency range of 30 MHz to 6 GHz) 1 Scope This part is applicable to any wireless communication device capable of transmitting electromagnetic fields (EMF) intended to be used at a position near the human body, in the manner described by the manufacturer, with the radiating part(s) of the device at distances up to and including 200 mm from a human body, i.e. when held in the hand or in front of the face, mounted on the body, combined with other transmitting or non-transmitting devices or accessories (e.g. belt-clip, camera or Bluetooth add-on), or embedded in garments. For transmitters used in close proximity to the human ear, the procedures of YD/T 1644.1 (IEC 62209-1:2005) are applicable. This standard is applicable for radio frequency exposure in the frequency range of 30 MHz to 6 GHz, and may be used to measure simultaneous exposures from multiple radio sources used in close proximity to human body. Definitions and evaluation procedures are provided for the following general categories of device types: body-mounted, body-supported, desktop, front-of-face, hand-held, laptop, limb-mounted, multi-band, push-to-talk, clothing-integrated. The types of devices considered include but are not limited to mobile telephones, cordless microphones, auxiliary broadcast devices and radio transmitters in personal computers. This part gives guidelines for a reproducible and conservative measurement methodology for determining the compliance of wireless devices with the SAR limits. Because studies suggest that exclusion of features to represent a hand in human models constitutes a conservative case scenario for SAR in the trunk and the head, a representation of a hand is not included if the device is intended to be used next to the head or supported on or near the torso [73], [80]. This part does not apply for exposures from transmitting or non-transmitting implanted medical devices. This standard does not apply for exposure from devices at distances greater than 200 mm away from the human body. This part makes cross-reference to YD/T 1644.1 (IEC 62209-1:2005) where complete clauses or subclauses apply, along with any changes specified. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced documents (including any amendments) applies. YD/T 1644.1-2007 Human exposure to radio frequency fields from hand-held and body-mounted wireless communication devices—Human models, instrumentation, and procedures—Part 1: Procedure to determine the specific absorption rate (SAR) for hand-held devices used in close proximity to the ear (frequency range of 300 MHz to 3 GHz) ISO/IEC 17025-1999 General requirements for the competence of testing and calibration laboratories 3 Terms and definitions For the purposes of this part, the following terms and definitions apply. 3.1 accessory optional component that can be used in conjunction with a transmitting device Accessories for mobile phones, wireless transmitting devices, wireless receiving devices or wireless transceiving devices, or two-way radios include the following: a) accessories for holding, affixing, or otherwise carrying, wearing or attaching the device, as well as providing spacing from the body (e.g. a belt-clip, wrist-strap or any other body strap, or lanyard for wearing the device as necklace); b) electronic accessories for performing tasks or which provide features (e.g., GPS modules, outboard printers, MP3 players, cameras or viewing devices); c) electronic accessories providing audio or video input or output (e.g., headsets, microphones, cameras); d) accessories providing enhanced RF capability to the device (e.g., replacement or auxiliary antennas); e) batteries and related d.c. power components; f) combinations of accessories, where two or more of the above are combined within one component (e.g., belt clip with built-in Bluetooth and “pigtail” audio cable to device). 3.2 body-mounted device body-worn device2) portable device containing a wireless transmitter or transceiver which is positioned in close proximity to a person’s torso or limbs (excluding the head) by means of a carry accessory during its intended use or operation of its radio functions   3.3 body-supported device a device whose intended use includes transmitting with any portion of the device being held directly against a user’s body This differs from a body-mounted device in that it is not attached to a user’s body by means of a carry accessory. 3.4 cable wire that is necessary for the functionality in the intended operational configuration 3.5 conservative exposure estimate of the peak spatial-average SAR, including uncertainties as defined in this standard, representative of and slightly higher than expected to occur in the bodies of a significant majority of persons during intended use of hand-held devices Conservative estimate does not mean the absolute maximum SAR value that could possibly occur under every conceivable combination of body size, body shape, wireless device orientation, and spacing relative to the body. In order to ensure that the results are not overly restrictive, and thereby unnecessarily inhibit the advancement of new mobile communications technologies, SAR overestimates should be as small as possible. For example, overestimates of the order of 20 % have been reported for head exposures [78], [79], and were deemed reasonable. Achieving an optimal compromise between over- or underestimate conditions is a complex task, which is why the conductivity of the tissue-equivalent liquid is not selected to be arbitrarily large, for example. 3.6 desktop device a device placed or mounted on a desk, table, or similar supporting structure, and the antenna of which is intended to be operated closer than 200 mm from the human body 3.7 device under test DUT a device that contains one or more wireless transmitters or transceivers that is subject to this standard A device under test may be further categorised as a body-worn, body-supported, desktop, front-of-face, hand-held, limb-worn, clothing-integrated or as a generic device. 3.8 duty factor operational time averaging factor the proportion of time that a transmitter transmits over a specified period 3.9 front-of-face device hand-held device operated in close proximity to the face Front-of-face device types include push-to-talk devices, two-way radios, devices equipped with a camera.   3.10 generic device a device that cannot be categorized as any of the specific device types 3.11 hand-held device a portable device which is located in a user’s hand during its intended use 3.12 host any equipment which has complete user functionality when not connected to the radio equipment part and to which the radio equipment part provides additional functionality and to which connection is necessary for the radio equipment part to offer functionality 3.13 intended use intended purpose use for which a product, process or service is intended according to the specifications, instructions and information provided by the manufacturer. Also, use of a device for the full range of available functions, in accordance with the specifications, instructions and information provided by the manufacturer Note 1: User guide instructions may include the intended use operating position and orientation. Note 2: Intended use, i.e. the way a manufacturer specifies that a device should be used may not encompass all possible use conditions. 3.14 laptop device portable computer a portable device containing one or more wireless transceivers, that can sit on the user’s lap and is not intended for hand-held use Laptop device types include laptop (notebook) computers, typically comprised of separate keyboard and display sections connected by hinge, and tablet computers, which typically have a one-section construction where the display section also serves as input interface using a stylus or virtual keyboard. 3.15 limb-mounted device a device whose intended use includes being strapped to the arm or leg of the user while transmitting (except in idle mode) Limb-mounted device types include wrist-mounted, ankl

Contents of YD/T 1644.2-2011

Foreword i Introduction ii 1 Scope 2 Normative references 3 Terms and definitions 4 Symbols and abbreviated terms 4.1 Physical quantities 4.2 Constants 4.3 Abbreviations 5 Measurement system specifications 5.1 General requirements 5.2 Phantom specifications (shell and liquid) 5.3 Measurement instrumentation system specifications 6 Protocol for SAR evaluation 6.1 Measurement preparation 6.2 Tests to be performed 6.3 Measurement procedures 6.4 Post-processing 7 Uncertainty assessment 7.1 General considerations 7.2 Components contributing to uncertainty 7.3 Uncertainty assessment 8 Measurement report 8.1 General 8.2 Contents to be recorded in the measurement report Annex A (Informative) Phantom rationale Annex B (Normative) Measurement system verification Annex C (Informative) Fast SAR testing Annex D (Informative) Standard sources and phantoms for system validation Annex E (Informative) Example recipes for phantom tissue-equivalent liquids Annex F (Normative) SAR correction for deviations of complex permittivity from targets Annex G (Informative) Hands-free kit testing Annex H (Informative) Skin enhancement factor Annex I (Informative) Tissue-equivalent liquid dielectric property measurements and measurement uncertainty estimation Annex J (Informative) Testing compliance for the exposure of the hand Annex K (Informative) Test reduction Annex L (Informative) Power scaling procedure Annex M (Informative) Rationale for probe parameters Bibliography