BS ISO 13165-3:2016 pdf download

BS ISO 13165-3:2016 pdf download.Water quality — Radium-226 — Part 3: Test method using coprecipitation and gamma- spectrometry
1 Scope
This part of ISO 13165 specifies the determination of radium-226 ( 226 Ra) activity concentration in all types of water by coprecipitation followed by gamma-spectrometry (see ISO 18589-3).
The method described is suitable for determination of soluble 226 Ra activity concentrations greater than 0,02 Bq l −1 using a sample volume of 1 l to 100 l of any water type.
For water samples smaller than a volume of 1 l, direct gamma-spectrometry can be performed following
ISO 10703 with a higher detection limit.
NOTE This test method also allows other isotopes of radium, 223 Ra, 224 Ra, and 228 Ra, to be determined.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples
ISO 10703, Water quality — Determination of the activity concentration of radionuclides — Method by high resolution gamma-ray spectrometry
ISO 11929, Determination of the characteristic limits (decision threshold, detection limit and limits of the confidence interval) for measurements of ionizing radiation — Fundamentals and application
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
ISO 80000-10, Quantities and units — Part 10: Atomic and nuclear physics
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 80000-10 and the following apply.
3.1 activity
number of spontaneous nuclear disintegrations occurring in a given quantity of material during a suitably small interval of time divided by that interval of time
[SOURCE: ISO 921:1997, 23]
3.2 reference standard
standard, generally having the highest metrological quality available at a given location or in a given organisation, from which measurements made there are derived
3.3 working standard
standard which, usually calibrated against a reference standard (3.2), is used routinely to calibrate or check material measures, measuring instruments or reference materials. It can be used as a solution of known activity (3.1) concentration obtained by precise dilution or dissolution of a reference standard
4 Symbols
For the purposes of this part of ISO 13165, the symbols defined in ISO 11929 and ISO 80000-10, and the following apply.
5 Principle of the measurement
Measurement of 226 Ra activity concentration in water is carried out in two separate steps: a sample preparation step, followed by a measurement by gamma-spectrometry. [13][14][15] The sample preparation consists of a filtration of the water sample (see ISO 5667-3) to ensure the measurement of the activity concentration of the 226 Ra soluble fraction. The filtration is followed by a pre-concentration, coprecipitation, and accumulation of decay products of 226 Ra. After filtration and acidification of the water sample, the 226 Ra is coprecipitated into sulfate using a carrier such as barium nitrate or carbonate. The radium and barium sulfates are then washed, dried, and weighed. The chemical yield is obtained gravimetrically. For water samples that may have an existing concentration of soluble barium, another tracer should be used to avoid a chemical yield above 100 %.