rijsttijd

Rijsttijd, in Dutch, corresponds to the English term rise time and describes how quickly a signal increases from a low to a high value. In technical contexts it is commonly defined as the time required for a signal to move from 10% to 90% of its final steady‑state amplitude. Some definitions use other windows (for example 0%–100% or 20%–80%), so the exact value should be specified when reporting rise time.

For a first‑order system such as a simple RC circuit, the rise time is approximately 2.2 times the time constant (rt ≈ 2.2 RC). Equivalently, rt ≈ 0.35 / f3dB, where f3dB is the 3‑dB bandwidth. In higher‑order networks, rise time depends on the pole positions and damping and may exhibit overshoot or ringing.

Measurement techniques rely on an oscilloscope or a data‑acquisition system with sufficient bandwidth. The probe, cables, and terminations can affect the measured value, so de‑embedding and proper calibration are essential. The input signal should have a fast rise relative to the system being measured to avoid attributing the rise time to the instrument.

Applications span digital logic and communications, where rise time limits data rate; analog and RF circuits, where it constrains bandwidth; optical detectors and laser systems, where impulse response matters; and mechanical actuators and control systems, where rise time relates to system speed.