5 Erzeugung und Erkennung des Prüfgas-Flusses
5.1 Prüfgas fließt in den Gegenstand (Gruppe-A-Techniken)
5.2 Prüfgas fließt aus dem Gegenstand (Gruppe-B-Techniken)
https://www.beuth.de/de/norm/din-en-iso-20485/278805559

J'ai trouvé le texte complet de la norme ISO 20485, malheureusement uniquement en anglais.
Extrait :

5 Generation and detection of tracer gas flow
5.1 Tracer gas flows into the object (Group A techniques)
A pressure difference across the wall is obtained either by evacuation of the object, e.g. through a connection or by placing it in a pressurized chamber. Usually the test object is evacuated. Tracer gas is then applied to the external surface using a probe jet or by enclosing the object (totally or partially) in a hood or chamber filled with the tracer gas. Tracer gas leakage into the test object is detected by a sensor within or connected to the internal volume.
5.2 Tracer gas flows out of the object (Group B techniques)
The object is filled with a tracer gas. A pressure difference across the wall is obtained either by pressurization of the object, e.g. through a connection or by placing it in a vacuum chamber. The tracer gas is collected on the outside surface by a sampling probe, a carrier gas flow or by accumulation into a hood or chamber. Tracer gas can also be detected by chemical reactions. A special technique (bombing) may also be used. This involves the pressurization of a sealed object to force the tracer gas into its internal cavities, if a leak exists. The object is then placed in a vacuum chamber and escaping tracer gas is detected (this procedure is generally used only with helium-4).
This method is applicable to specimens with small free internal volumes (in the order of a few cubic centimetres).
https://cdn.standards.iteh.ai/samples/68190/cf45f5794bcb4122...

German Search: "Vorfluter"
Your search has returned no results.
https://www.iso.org/obp/ui/#home
(c'est-à-dire ne figurant dans aucune publication de l'ISO)

J'ai trouvé le terme "Vorfluter" dans tous les dictionnaires uniquement dans le contexte de l'hydrologie.

Vorfluter (Umwelt, Wasserb) / outfall, receiving water
(Kucera, Dictionary of Exact Science and Technology)

outfall (hydr) / canal de fuite, canal émissaire
(Ernst, Dictionnaire Général de la Technique Industrielle)

Vorfluter m (Wasserb) / canal de derivation, canal émissaire
(Kucera, Dictionnaire Compact, des Sciences et de la Technique)

Vorfluter m Abwasser / cours m d'eau récepteur, milieu m récepteur, collecteur m
(UniLex Pro Brandstetter)

l'émissaire m. [UMWELT] der Hauptsammler Pl.: die Hauptsammler [Abwasser]
https://dict.leo.org/französisch-deutsch/émissaire

main drain der Hauptsammler Pl.: die Hauptsammler
main sewer [TECH.] der Hauptsammler Pl.: die Hauptsammler
interceptor sewer [TECH.] der Hauptsammler Pl.: die Hauptsammler
main collector der Hauptsammler Pl.: die Hauptsammler [Abwasser]
https://dict.leo.org/englisch-deutsch/Hauptsammler
(Aucun des termes figurant dans la norme ISO 20485.)