Kierroskynnys

Kierroskynnys is a Finnish term formed from kierros (rotation, revolution) and kynnys (threshold, limit). It refers to a threshold value related to rotation or revolutions and is used in various technical contexts to describe the point at which rotational movement is recognized, initiated, or measured.

In mechanical design and engineering, kierroskynnys can denote the minimum angular movement required to overcome static friction, backlash, or other resistance so that motion begins or reaches a new position. It may also describe the smallest rotation needed to produce a detectable change in a mechanism’s state, such as a valve, linkage, or geared assembly.

In sensing, metrology, and control systems, kierroskynnys often refers to the smallest detectable rotation by a sensor or the minimum step size that a control system or encoder must register to count a rotation. This usage is common in rotary encoders, stepper motor applications, and precision measurement setups, where the threshold determines when a turn is acknowledged as a full step or a completed cycle.

In practice, the exact meaning of kierroskynnys depends on the context and the specific device or procedure being described. It is a descriptive term rather than a standardized specification, and it is sometimes translated into English as “rotation threshold” or “start-up angle,” depending on the application.

See also: threshold, rotation, angular motion, encoder, backlash.