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The standard defines specifications, modeling methods and terminology for the dispersion of specified instants of repetitive and/or periodic signals in electronics, telecommunications and measurement, which is referred to as jitter and phase noise.

定价： 66元 / 折扣价： 57 元

定价： 53元 / 折扣价： 46 元

Noise is a limiting factor in any system which stores information because it limits the signal-to-noise ratio and hence the total quantity of stored data. This applies in the field of sound recording and reproducing, as well as in any information storage system

定价： 55元 / 折扣价： 47 元

定价： 73元

This standard provides techniques to select wind turbine and wind farm aero acoustic noise measurements, including instrumentation standards and metrology technology, measurement set, measurement procedures, data processing, and noise source data analysis. The scope of measurement covers near-field sound measurement similar to IEC 61400-11 and distance and far-field sound measurement both outside and inside concerned houses or buildings. This standard focuses on amplitude modulation noise,… read more however, guidelines for low-frequency noise including infrasound near-field measurement are provided. IEC 61400-11 provides overall wind turbine noise measurement standards, while this standard focuses more on the aero acoustic noise of wind turbines to avoid overlap with IEC 61400-11. Users of this standard should also be familiar with of ANSI S1.1-1994 (R2004), Acoustical Terminology. read less

定价： 56元 / 折扣价： 48 元

This standard describes manual and automated procedures for measuring audible noise from overhead power transmission lines.

定价： 57元 / 折扣价： 49 元

定价： 116元 / 折扣价： 99 元

This standard establishes uniform procedures for the measurement of radio noise generated by corona from overhead power lines and substations. Measurement procedures in this standard are also valid for other power-line noise sources such as gaps and harmonics; however, most of the precautionary information, analysis, and data plotting techniques were written and developed primarily for corona discharges. The procedures are not valid for measuring transient radio noise sources that occur during… read more breaker or disconnect switching operations. The procedures apply in the frequency range of 0.010 MHz to 1000 MHz; however, the emphasis is on the standard amplitude-modulation broadcasting (0.535 MHz to 1.605 MHz) and television broadcasting (54 MHz to 72 MHz, 76 MHz to 88 MHz, 174 MHz to 216 MHz, and 470 MHz to 698 MHz) bands. This standard is applicable to both ac and dc transmission lines and substations. read less

定价： 65元 / 折扣价： 56 元

定价： 56元 / 折扣价： 48 元

The practice described herein provides instruction for the testing of distribution transformers as sources of voice frequency noise. These tests measure the degree to which a transformer may contribute to electrical noise in communication circuits that are physically paralleling the power-supply circuits feeding the transformer. Transformers have a characteristic that is common to other iron-core devices of causing harmonic currents at voice frequencies to flow in supply circuits to the transformers. The magnitude of these currents, and of interference that may result, varies according to the design of the transformer as well as the excitation voltage. The tests described in this practice provide a standard method for use by the transformer manufacturer, user, and others in industry for the purpose of better evaluating the design choices that are available and moving toward industry objectives with regard to levels of harmonic exciting current expressed as I · T (current x telephone influence factor [TIF]).

定价： 158元 / 折扣价： 135 元

The purpose of this document is to develop a guide for the installation and operation of industrial controllers to minimize the disturbing effects of electrical noise on these controllers.

定价： 162元 / 折扣价： 138 元