Waveform measurement — rise time definition: The rise time on the leading edge of a digital pulse is measured from 10% to 90% of its amplitude. Decide whether this definition is accurate.

Introduction / Context:
Rise time is a standard timing parameter for digital and analog step responses. Most instrumentation defines it between 10% and 90% of final amplitude to avoid noise and saturation effects at the extremes.

Given Data / Assumptions:

• A pulse transitions from a low level to a high level.
• Amplitude is the steady-state difference between final and initial levels.
• Industry-common definition uses 10%–90% markers; some instruments also support 20%–80% for bandwidth calculations.

Concept / Approach:
Measuring from 10% to 90% minimizes sensitivity to initial baseline noise and final top-flat saturation. Many bandwidth formulas relate system bandwidth to 10%–90% rise time via empirical constants for simple first-order systems.

Step-by-Step Solution:

Verification / Alternative check:
Compare with datasheets: oscilloscopes commonly list rise-time measurement as 10%–90% with an optional 20%–80% mode for specific bandwidth estimation workflows.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing rise time with propagation delay; measuring on a noisy trace without averaging or proper triggering.

Final Answer:
Correct