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This standard describes a method of measuring the amplitude levels of an SMPTE 170M-1994,1 NTSC color or monochrome television video signal. It is concerned with luminance measurements at various points in transmission systems where the signals are at video frequencies. The methods described in this standard are limited to the use of waveform monitors, software video processing for amplitude assessment, or suitable oscilloscopes, and are primarily directed to specifying means of measuring… read more television signal levels for operating purposes. read less

定价： 141元 / 折扣价： 120 元

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This recommended practice presents a rationale for developing emission limits and immunity test levels and recommends that these facets are representative of current practice and user needs. Emission limits generally are written by national and international standards bodies. Emission limits for the most part are specified by regulators, which is the case in the U.S. and Canada. Such regulatory limits take precedence, even if the limits are different from those considered in this document. In the U.S. and Canada, product immunity is not regulated except for some safety equipment. In this way, adequate immunity is more a quality aspect of the product as if it does not operate in its intended RF environment, the user would deem it of poor quality. It should be noted that the entire document does not impose normative requirements, but recommends options.

定价： 65元 / 折扣价： 56 元

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This standard provides a general intelligence level architecture for smart home devices, in order to stipulate their capabilities equipped by various sensors, hardware and software. The standard specifies home device intelligence capabilities mainly from seven aspects, including computation, perception, cognition, motion, coordination, skills, and security. -The computation comprises of computing, memory, storage, and network components. -The perception includes speech and vision. -The… read more cognition is enabled by natural language processing and other related technologies. -The motion involves decision-making and route planning. -The coordination describes how the device interacts with others. -The skills refer to study, education, entertainment, and others based on the type and domain of devices. -The security includes electromagnetic compatibility and system security. read less

定价： 58元 / 折扣价： 50 元

This guide, covering three-phase ac systems from 1 kV to 800 kV, provides recommended electrical operating, safety clearances, and insulation levels in air-insulated electric supply substations; addresses insulation coordination procedures; provides design procedures for the selection and coordination of the insulation levels within the station as they relate to substation clearances; and addresses how reduced clearances in highvoltage ac substations will allow for compact bus arrangements and… read more substation voltage uprating applications. This guide addresses insulation coordination procedures, including the choice of insulation levels and arrester specification, in limited detail and only as relevant to clearance requirements. Detailed and expanded coverage of insulation coordination procedures is provided in other ANSI and IEEE guides and standards (see Clause 2). This guide focuses on open-air bus assemblies and configurations and excludes apparatus clearances (i.e., bushing clearances for transformers, and breakers). Detailed coverage of apparatus clearances is provided in other applicable guides and standards. read less

定价： 75元 / 折扣价： 64 元

Develop safety levels for human exposure to electromagnetic fields from 0 to 3kHz. This standard will be based on the results of an evaluation of the relevant scientific literature and proven effects which are well established and for which thresholds of reaction are understood. Field limits will be derived from threshold current densities or internal electric fields.

定价： 101元 / 折扣价： 86 元

Develop revised maximum permissible exposure (MPE) levels for exposures to electromagnetic fields for exposures in controlled and uncontrolled environments at frequencies between 3 kHz and 300 Ghz. The MPEs will be expressed in terms of quantifiable parameters such as electric-field strength, magnetic-field strength, power density, induced current and contact current. Exclusions and peak limits for pulsed fields will be included.

定价： 104元 / 折扣价： 89 元

This part of ISO/IEC 15026 specifies the concept of integrity levels with corresponding integrity level requirements that are required to be met in order to show the achievement of the integrity level. It places requirements on and recommends methods for defining and using integrity levels and their integrity level requirements. It covers systems, software products, and their elements, as well as relevant external dependences.This part of ISO/IEC 15026 is applicable to systems and software and… read more is intended for use by:a) definers of integrity levels such as industry and professional organizations, standards organizations, and government agencies;b) users of integrity levels such as developers and maintainers, suppliers and acquirers, users, and assessors of systems or software and for the administrative and technical support of systems and/or software products.One important use of integrity levels is by suppliers and acquirers in agreements; for example, to aid in assuring safety, economic, or security characteristics of a delivered system or product.This part of ISO/IEC 15026 does not prescribe a specific set of integrity levels or their integrity level requirements. In addition, it does not prescribe the way in which integrity level use is integrated with the overall system or software engineering life cycle processes. It does, however, provide an example of use of this part of ISO/IEC 15026 in Annex A. read less

定价： 0元 / 折扣价： 0 元

This standard specifies exposure criteria and limits to protect against established adverse health effects in humans associated with exposure to electric, magnetic, and electromagnetic fields in the frequency range of 0 Hz to 300 GHz.1,2 These limits, incorporating safety margins, are expressed in terms of dosimetric reference limits (DRL) and exposure reference levels (ERL). DRLs are expressed in terms of in situ electric field strength, specific absorption rate (SAR), and epithelial power density. ERLs, which are more easily determined, are limits on external electric and magnetic fields, incident power density, induced and contact currents, and contact voltages intended to ensure that the DRLs are not exceeded. The limits, which protect against adverse health effects associated with electrostimulation of tissue and local and whole-body heating, are intended to apply to the described human exposure conditions. However, these levels are not intended to address exposures of patients or human research subjects under the care of medical professionals for which other risks and benefits might apply. These exposure limits might not prevent interference with medical and other devices that might exhibit susceptibility to electromagnetic interference (EMI).

定价： 370元 / 折扣价： 315 元