IEC 61874:1998 pdf download - Nuclear instrumentation - Geophysical borehole instrumentation to determine rock density (“density logging")

IEC 61874:1998 pdf download – Nuclear instrumentation – Geophysical borehole instrumentation to determine rock density (“density logging”)

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IEC 61874:1998 pdf download – Nuclear instrumentation – Geophysical borehole instrumentation to determine rock density (“density logging”).
– borehole logging probe equipped with a collimated radioisotope (gamma) source (during the actual measurements only) and a detector unit to measure scattered gamma radiahon:
— coaxial cable with winch and deplh control:
– other instruments and devices (power supply, pulse converter/amplifier, ratemeter. recorder, signal processing and readout units),
This standard defines the terminology, specifies the types of apparatus, design and general technical requirements, specific radiation performance, electrical, mechanical and environmental performance requirements. It also defines test and calibration procedures and covers electrical safety and radiation protection issues. Further, ii gives recommendations about items that should be included in the manufacturer’s operation and maintenance documentation (or certificate).
The purpose of this standard is to specify design requirements and performance characteristics of nuclear instrumentation used in boreholes to determine bulk rock density in situ. With suitable response charts the measurements can be equated to rock lithology and porosity.
2 NormatIve references
The following normative documents contain provisions which, through reference in this text, constitute provisions 01 this International Standard. At the time of publication, the edit,ons indicated were valid. All normative documents are subjGct to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 60050(393): 1996, Inlernazional Electrotechnical Vocabulary (1EV) — Chapter 393: Nuclear instrumentation: Physical phenomena and basic concepts
IEC 60050(394):1995, International Electrotechnical Vocabulary (1EV) — Chapter 394: Nuclear instrumentation: Instruments
IEC 60359:1987. Expression of the performance of electrical and electronic measuring equipment
IEC 60405:1972, Nuclear instruments: Constructional requirements to afford personal protection against ionizing radiation
3 DefinitIons
Except as defined below, all technical terms are defined In IEC 60050, partIcularly IEC 60050(393) and IEC 60050(394), and IEC 60359. For the purpose of this standard the following definitions apply.
density logging
irradiation of the rock formations surrounding the borehole with a constant flux of medium energy gamma rays from a sealed radioisotope source and counting the number of scattered gamma rays that reach a detector positioned at some distance. The measurements are carried out by moving the source-detector assembly (.logging probe) along the borehole wall.
working range
the range of bulk density of rocks in which the measurements are carried out with specified accuracy
rated operating conditions
a set of working range operating characleri5tic5 for all influence quantities within which the
instrument specified errors are maintained
rated operating range
the whole of working ranges for quantities to be measured within which the performance of the apparatus is specified
basic error
the error determined under test conditions
test conditions
the set of influence quantity values and parameters with specified variation limits at which the calibration is carried Out
operating error
the error of a performance characteristic which is obtained at any point within the rated operating conditions
intrinsic error
the error of a measuring instrument when used under reference conditions
reference Conditions
the appropriate set of influence quantities and performance characteristics, with reference values with their tolerances and reference ranges. with respect to which the intrinsic error is specified.

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