läpäisymitataan

Läpäisymitataan is a Finnish term used mainly in materials science and engineering to describe the process of determining a material’s permeability or transmittance. The word combines läpäisy, meaning permeability or transmittance, with mitata, “to measure,” and is often encountered in passive constructions such as läpäisymitataan, meaning “the permeability is measured.” The term is relatively specialized and not part of everyday Finnish, and its exact meaning can vary by context.

In practice, läpäisymitataan refers to assessing how readily a substance—such as a gas, vapor, moisture, or liquid—passes through a material. It is central to evaluating barrier properties of films, membranes, coatings, packaging, textiles, and electronic enclosures. Measurements can target gas permeability (e.g., oxygen or carbon dioxide), water vapor transmission, or other diffusive or sorptive properties. Common methods include permeation tests with constant-volume or constant-pressure cells, diffusion-based experiments, and spectroscopic or tracer techniques. Instruments often used are permeation analyzers and gas-permeation testers, operated under controlled temperature and humidity.

Standards for permeability measurements exist under international and national bodies (ISO, ASTM, DIN, etc.), and the choice of standard depends on material, test gas, and application. As a term, läpäisymitataan is primarily used by Finnish-speaking professionals and may appear in technical reports, theses, and industry specifications. Note that some writers prefer to separate the phrases läpäisy and mitata or to use the passive form läpäisy mitataan depending on style and register.