NBN ISO 23696-2:2023

< p class=" MsoBodyText" style=" mso-layout-grid-align: none text-autospace: none " > < span lang=" EN-GB" style=" mso-bidi-font-size: 12.0pt " > This document specifies a method for the determination of nitrate as NO< sub> 3< / sub> -N in water of various origin such as natural water (including groundwater, surface water and bathing water), drinking water and wastewater, in a measuring range of concentration between 0,20 mg/ l and 30 mg/ l of NO< sub> 3< / sub> -N using the small-scale sealed tube method. Different measuring ranges of small-scale sealed tube methods can be required.< / span>

< p class=" MsoBodyText" style=" mso-layout-grid-align: none text-autospace: none " > < span lang=" EN-GB" style=" mso-bidi-font-size: 12.0pt " > The measuring ranges can vary depending on the type of the small-scale sealed tube method of different manufacturers.< / span>

< p class=" MsoBodyText" style=" mso-layout-grid-align: none text-autospace: none " > < span lang=" EN-GB" style=" mso-bidi-font-size: 12.0pt " > It is up to the user to choose the small-scale sealed tube test with the appropriate application range or to adapt samples with concentrations exceeding the measuring range of a test by preliminary dilution.< / span>

< p class=" Note" style=" tab-stops: 19.85pt 39.7pt 48.25pt 59.55pt 79.4pt 99.25pt 119.05pt 138.9pt 158.75pt 178.6pt 7.0cm mso-layout-grid-align: none text-autospace: none " > < span lang=" EN-GB" style=" mso-bidi-font-size: 12.0pt " > NOTE 1< span style=" mso-tab-count: 1 " >    < / span> The results of a small-scale sealed tube test are most precise in the middle of the application range of the test.< / span>

< p class=" MsoBodyText" style=" mso-layout-grid-align: none text-autospace: none " > < span lang=" EN-GB" style=" mso-bidi-font-size: 12.0pt " > Manufacturers' small-scale sealed tube methods are based on chromotropic colour reaction, depending on the typical operating procedure of the small-scale sealed tube used, see < span class=" citesec" > < span style=" color: black mso-color-alt: windowtext border: none " > < span style=" border: none " > Clause 9< / span> < / span> < / span> .< / span>

< p class=" Note" > < span lang=" EN-GB" > NOTE 2< span style=" mso-tab-count: 1 " >       < / span> Laws, regulations or standards can require that the data is expressed as NO< sub> 3< / sub> after conversion with the stoichiometric conversion factor 4,426 81 in < / span> < span class=" citesec" > < span lang=" EN-GB" style=" mso-bidi-font-size: 12.0pt color: black mso-color-alt: windowtext border: none " > < span style=" border: none " > Clause 11< / span> < / span> < / span> < span lang=" EN-GB" > .< / span>

< p class=" Note" style=" tab-stops: 19.85pt 39.7pt 48.25pt 59.55pt 79.4pt 99.25pt 119.05pt 138.9pt 158.75pt 178.6pt 7.0cm mso-layout-grid-align: none text-autospace: none " > < span lang=" EN-GB" style=" mso-bidi-font-size: 12.0pt " > NOTE 3< span style=" mso-tab-count: 1 " >    < / span> In the habitual language, use of sewage treatment and on the displays of automated sealed-tube test devices, NO< sub> 3< / sub> without indication of the negative charge has become the common notation for the parameter nitrate and especially for the parameter nitrate-N. This notation is adopted in this document even though not being quite correct chemical nomenclature.< / span>