Measurement systems — dynamic vs static characteristics Among the listed properties, which one is a dynamic characteristic describing how an instrument follows time-varying inputs?

Introduction / Context:
Instrumentation performance is described by static and dynamic characteristics. Knowing the difference helps in selecting and tuning sensors and measurement chains for real-time processes.

Given Data / Assumptions:

• Static traits relate to steady-state inputs (e.g., sensitivity, accuracy, reproducibility, dead zone).
• Dynamic traits relate to time-varying signals (e.g., speed of response, lag, fidelity, bandwidth).

Concept / Approach:
Fidelity describes how accurately an instrument reproduces the time-dependent variations of the input without distortion. High fidelity means the output waveform matches the input waveform across the relevant frequency band.

Step-by-Step Solution:
Classify each option: reproducibility (static repeatability), sensitivity (static input–output slope), dead zone (static insensitivity region), fidelity (dynamic tracking).Select the dynamic characteristic → fidelity.

Verification / Alternative check:
Control systems and measurement textbooks define fidelity within dynamic response metrics together with lag and bandwidth.

Why Other Options Are Wrong:

• Reproducibility: ability to give the same reading under unchanged conditions (static).
• Sensitivity: gain at steady state (static).
• Dead zone: input range not producing output (static nonlinearity).

Common Pitfalls:

• Confusing high sensitivity with ability to track fast signals; a very sensitive instrument can still have poor dynamic response.

Final Answer:
Fidelity