{"query_echo":{"q":"","filters":{"analysis_type":["validation"]},"warnings":[{"code":"facet_value_not_in_vocabulary","message":"Value 'validation' for facet 'analysis_type' is not in the controlled vocabulary."}]},"total":{"value":1,"relation":"eq"},"page":1,"page_size":20,"self":"https://climateinsightsdirectory.org/api/v1/search?analysis_type=validation","stability":"beta","ai_marking":{"digital_source_type":{"uri":"http://cv.iptc.org/newscodes/digitalsourcetype/trainedAlgorithmicMedia","name":"Created using Generative AI"},"notice":"Summary and key insights are generated using artificial intelligence."},"results":[{"id":"client-000750","url":"https://climateinsightsdirectory.org/document/client-000750","title":"Brussels measurement campaign methodology","publisher":{"name":"ClientEarth","organization":"clientearth"},"document_type":"briefing","language":"en","date_published":"2017-06","source_url":"https://www.clientearth.org/media/s1am2jco/methodology-brief-for-brussels-air-quality-monitoring-2017-ce-en.pdf","generator":"Climate Insights Directory","generated_fields":["summary","key_insights","analysis_type"],"summary":{"text":"The document describes the use of Palmes-type NO2 diffusion tubes to monitor air quality across several Brussels locations from 19 February to 20 March 2017. It details the placement of tubes according to Directive 2008/50/EC, the laboratory analysis by Gradko International Limited, and a validation process at the Avenue de la Couronne station which revealed a 24% under-estimation of concentrations by the diffusion tubes. ClientEarth notes it adopted a conservative approach by using the lowest recorded concentrations for locations with multiple samples and publishing raw data without applying the bias correction factor.","ai_generated":true,"unit":"client-000750#summary","date_modified":"2026-10-23"},"key_insights":[{"text":"The measurement campaign utilized Palmes-type nitrogen dioxide (NO2) diffusion tubes, which the European Environment Agency categorizes as an \"indicative\" monitoring technique with a margin of uncertainty of ± 25%.","ai_generated":true,"unit":"client-000750#insight-1","date_modified":"2026-10-23"},{"text":"Monitoring took place over four weeks between 19 February and 20 March 2017, with sampling points located at Rue Belliard, Rue de la Loi, Arts-Loi, Avenue des Arts, the Esplanade of the European Parliament, and Avenue de la Couronne.","ai_generated":true,"unit":"client-000750#insight-2","date_modified":"2026-10-23"},{"text":"Sampling points were sited according to Directive 2008/50/EC, specifically placed 2.5 m above ground, within 10 m of the kerbside, and at least 25 m from the edge of major junctions.","ai_generated":true,"unit":"client-000750#insight-3","date_modified":"2026-10-23"},{"text":"Validation at the Avenue de la Couronne official monitoring station showed that the diffusion tubes under-estimated actual NO2 concentrations by 24%, as the tubes recorded between 41.6 and 43.1 ±g/m3 while the official station recorded 52.5 ±g/m3.","ai_generated":true,"unit":"client-000750#insight-4","date_modified":"2026-10-23"}],"climate_tags":[],"geography_discussed":[],"frame_perspective":[],"analysis_type":["methodology","validation"]}]}