Metrologi och mätning. Fysikaliska fenomen

This document specifies an engineering method for calculating the attenuation of sound during propagation outdoors in order to predict the levels of environmental noise at a distance from a variety of sources. The method predicts the equivalent continuous A-weighted sound pressure level (as described in ISO 1996-series) under meteorological conditions favourable to propagation from sources of known sound emission. These conditions are for downwind propagation or, equivalently, propagation under a well-developed moderate ground based temperature inversion, such as commonly occurs in clear, calm nights. Inversion conditions over extended water surfaces are not covered and may result in higher sound pressure levels than predicted from this document (see e.g. References [11] and [12]). The method also predicts a long-term average A weighted sound pressure level as specified in ISO 1996-1 and ISO 1996-2. The long-term average A weighted sound pressure level encompasses levels for a wide variety of meteorological conditions. Guidance has been provided to derive a meteorological correction based on the angular wind distribution relevant for the reference or long-term time interval as specified in ISO 1996-1:2016, 3.2.1 and 3.2.2. Examples for reference time intervals are day, night, or the hour of the night with the largest value of the sound pressure level. Long-term time intervals over which the sound of a series of reference time intervals is averaged or assessed representing a significant fraction of a year (e.g. 3 months, 6 months or 1 year). The method specified in this document consists specifically of octave band algorithms (with nominal mid-band frequencies from 63 Hz to 8 kHz) for calculating the attenuation of sound which originates from a point sound source, or an assembly of point sources. The source (or sources) may be moving or stationary. Specific terms are provided in the algorithms for the following physical effects: — geometrical divergence; — atmospheric absorption; — ground effect; — reflection from surfaces; — screening by obstacles. Additional information concerning propagation through foliage, industrial sites and housing is given in Annex A. The directivity of chimney-stacks to support the sound predictions for industrial sites has been included with Annex B. An example how the far-distance meteorological correction C0 can be determined from the local wind-climatology is given in Annex C. Experiences of the last decades how to predict the sound pressure levels caused by wind turbines is summarized in Annex D. The method is applicable in practice to a great variety of noise sources and environments. It is applicable, directly, or indirectly, to most situations concerning road or rail traffic, industrial noise sources, construction activities, and many other ground-based noise sources. It does not apply to sound from aircraft in flight, or to blast waves from mining, military, or similar operations. To apply the method of this document, several parameters need to be known with respect to the geometry of the source and of the environment, the ground surface characteristics, and the source strength in terms of octave band sound power levels for directions relevant to the propagation. If only A weighted sound power levels of the sources are known, the attenuation terms for 500 Hz may be used to estimate the resulting attenuation. The accuracy of the method and the limitations to its use in practice are described in Clause 9.

This document specifies a screening test method to quantify rapidly the activity concentration of gamma emitting radionuclides, such as 131I, 132Te, 134Cs and 137Cs, in solid or liquid test samples using gamma ray spectrometry with lower resolution scintillation detectors as compared with the HPGe detectors (see IEC 61563[7]). This test method can be used for the measurement of any potentially contaminated environmental matrices (including soil), food and feed samples as well as industrial materials or products that have been properly conditioned.[8] Sample preparation techniques used in the screening method are not specified in this document, since special sample preparation techniques other than simple machining (cutting, grinding, etc.) should not be required. Although the sampling procedure is of utmost importance in the case of the measurement of radioactivity in samples, it is out of scope of this document; other international standards for sampling procedures that can be used in combination with this document are available (see References [9], [10], [11], [12], [13], [14]). The test method applies to the measurement of gamma-emitting radionuclides such as 131I, 134Cs and 137Cs. Using sample sizes of 0,5 l to 1,0 l in a Marinelli beaker and a counting time of 5 min to 20 min, decision threshold of 10 Bq·kg−1 can be achievable using a commercially available scintillation spectrometer [e.g. thallium activated sodium iodide (NaI(Tl)) spectrometer 2” ϕ × 2” (50,8 mm Ø x 50,8 mm) detector size, 7 % resolution (FWHM) at 662 keV, 30 mm lead shield thickness]. This test method also can be performed in a “makeshift” laboratory or even outside a testing laboratory on samples directly measured in the field where they were collected. During a nuclear or radiological emergency, this test method enables a rapid measurement of the activity concentration of potentially contaminated samples to check against operational intervention levels (OILs) set up by decision makers that would trigger a predetermined emergency response to reduce existing radiation risks[2]. Due to the uncertainty associated with the results obtained with this test method, test samples requiring more accurate test results can be measured using high-purity germanium (HPGe) detectors gamma-ray spectrometry in a testing laboratory, following appropriate preparation of the test samples[15][16]. This document does not contain criteria to establish the activity concentration of OILs.

 This document establishes the default specification operator (see ISO 17450-2) and defines a special specification operator for linear sizes. It applies to the following features of linear size: — cylinders, — spheres, — two parallel opposite planes. Annex C handles the definition of sizes for circles as sections of a cone. Annex D handles the definition of sizes for circles as sections of a torus. Annex E handles the definition of sizes for parallel opposite lines as longitudinal sections of cylindrical tubes in half planes containing a specified axis. This part of ISO 14405 provides a set of tools to express several types of linear size characteristics. It does not present any information on the relationship between a function or a use and a linear size characteristic.

ISO 16610-22:2015 specifies spline filters for the filtration of profiles. It specifies in particular how to separate the long- and short-wave component of a profile.