testikäyttöön

Testikäyttöön is a Finnish term that literally means "for testing use." It is formed from the words testi (test) and käyttö (use) with the illative suffix -öön, which in Finnish expresses purpose or direction. The phrase describes something that is intended to be used only for testing, rather than in normal production or everyday use.

It is commonly seen on hardware prototypes, experimental software builds, laboratory equipment, or in documentation to signal that an item is part of a testing phase. Items labeled testikäyttöön may have temporary or restricted availability and are often accompanied by further instructions about handling, data collection, or disposal after testing.

Grammatical forms include the adverbial illative "testikäyttöön" meaning "for testing use," and the related expressions such as "testikäyttöön tarkoitettu" (intended for testing) or "testikäyttöön tarkoitetut laitteet" (devices intended for testing). The form can be used to describe products, software, or procedures undergoing evaluation.

In English, equivalents include "for testing purposes" or "for test use" and, on labels, "test-use only" to indicate restricted deployment.

See also: Finnish language compounding, illative case, product testing, lab equipment.