{"id":41,"date":"2024-04-03T23:09:24","date_gmt":"2024-04-03T20:09:24","guid":{"rendered":"https:\/\/sisu.ut.ee\/measurement\/9-iso-gum-modeling-approach-bottom-approach\/"},"modified":"2024-06-19T16:37:34","modified_gmt":"2024-06-19T13:37:34","slug":"9-iso-gum-modeling-approach-bottom-approach","status":"publish","type":"page","link":"https:\/\/sisu.ut.ee\/measurement\/9-iso-gum-modeling-approach-bottom-approach\/","title":{"rendered":"9. The ISO GUM Modeling approach"},"content":{"rendered":"<p>This section presents step by step the modeling approach to measurement uncertainty estimation. This approach is described in detail in the ISO GUM<sup>(2)<\/sup> and has been interpreted for chemistry in the Eurachem measurement uncertainty guide<sup>(3)<\/sup>. It is often called also the \u201cbottom-up\u201d approach. This means that the uncertainties of the input quantities are found and thereafter combined into the combined standard uncertainty. The uncertainty estimation carried out in section 4 in principle also used this approach. The presentation in this section is based on a practical example \u2013 determination of ammonium nitrogen in water.<\/p>\n<ul>\n<li><a style=\"line-height: 1.6em;\" title=\"\" href=\"https:\/\/sisu.ut.ee\/measurement\/91-measurand-model-sources-uncertainty\/\">9.1. Step 1\u2013 Measurand definition<\/a><\/li>\n<li><a style=\"line-height: 1.6em;\" title=\"\" href=\"https:\/\/sisu.ut.ee\/measurement\/92-estimation-uncertainty-contributions-and-combined-standard-uncertainty-using-data-are\/\">9.2. Step 2 \u2013 Model equation<\/a><\/li>\n<li><a style=\"line-height: 1.6em;\" title=\"\" href=\"https:\/\/sisu.ut.ee\/measurement\/93-practical-example\/\">9.3. Step 3 \u2013 Uncertainty sources<\/a><\/li>\n<li><a style=\"line-height: 1.6em;\" title=\"\" href=\"https:\/\/sisu.ut.ee\/measurement\/94-step-4-finding-values-input-quantities\/\">9.4. Step 4 \u2013 Values of the input quantities<\/a><\/li>\n<li><a style=\"line-height: 1.6em;\" title=\"\" href=\"https:\/\/sisu.ut.ee\/measurement\/95-step-5-standard-uncertainties-input-quantities\/\">9.5. Step 5 \u2013 Standard uncertainties of the input quantities<\/a><\/li>\n<li><a style=\"line-height: 1.6em;\" title=\"\" href=\"https:\/\/sisu.ut.ee\/measurement\/96-step-6-calculating-value-output-quantity\/\">9.6. Step 6 \u2013 Value of the output quantity<\/a><\/li>\n<li><a style=\"line-height: 1.6em;\" title=\"\" href=\"https:\/\/sisu.ut.ee\/measurement\/97-step-7-calculating-combined-standard-uncertainty\/\">9.7. Step 7 \u2013 Combined standard uncertainty<\/a><\/li>\n<li><a style=\"line-height: 1.6em;\" title=\"\" href=\"https:\/\/sisu.ut.ee\/measurement\/98-step-8-finding-expanded-uncertainty\/\">9.8. Step 8 \u2013 Expanded uncertainty<\/a><\/li>\n<li><a style=\"line-height: 1.6em;\" title=\"\" href=\"https:\/\/sisu.ut.ee\/measurement\/99-step-9-analysis-uncertainty-sources-and-conclusions\/\">9.9. Step 9 \u2013 Looking at the obtained uncertainty<\/a><\/li>\n<\/ul>\n<p>The slides used in this section can be downloaded from\u00a0here:<\/p>\n<p>\u00a0<\/p>\n\n\n<div class=\"wp-block-group attached-files-group is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-file\"><a id=\"wp-block-file--media-852770ed-9e8d-4286-b893-2d488d650e83\" href=\"https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/18\/uncertainty_of_photometric_nh4_determination_iso_gum_modeling.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">uncertainty_of_photometric_nh4_determination_iso_gum_modeling.pdf<\/a><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>This section presents step by step the modeling approach to measurement uncertainty estimation. This approach is described in detail in the ISO GUM(2) and has been interpreted for chemistry in the Eurachem measurement uncertainty guide(3). It is often called also &#8230;<\/p>\n","protected":false},"author":14,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"class_list":["post-41","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/pages\/41","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/users\/14"}],"replies":[{"embeddable":true,"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/comments?post=41"}],"version-history":[{"count":3,"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/pages\/41\/revisions"}],"predecessor-version":[{"id":694,"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/pages\/41\/revisions\/694"}],"wp:attachment":[{"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/media?parent=41"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}