Dynamic measurement quality: the degree to which an instrument reproduces changes in the measured variable with no dynamic distortion (i.e., the output waveform is a faithful copy of the input) is called its what?

Introduction / Context:
In instrumentation, terminology distinguishes between how fast, how accurately, and how truthfully an instrument tracks a varying signal. When the concern is whether the output waveform is a faithful replica of the input (scaled and possibly delayed), we speak of fidelity—a critical attribute for dynamic measurements, audio systems, and control loops.

Given Data / Assumptions:

• Measured variable varies with time.
• We care about waveform integrity, not merely steady-state accuracy.
• Definitions follow standard measurement and control textbooks.

Concept / Approach:
Fidelity is the property that an instrument’s output accurately represents the input without dynamic error such as overshoot, lag-induced distortion, or bandwidth limitations. While speed of response concerns how quickly the output settles, and reproducibility concerns consistency of repeated measurements, fidelity emphasizes accurate waveform reproduction across the frequency content of interest.

Step-by-Step Solution:
Identify required attribute: truthful, undistorted following of input changes.Map attribute to term: fidelity.Confirm other terms do not specifically denote freedom from dynamic distortion.

Verification / Alternative check:
System identification texts equate high fidelity with flat amplitude response and linear phase within the band of interest, minimizing waveform distortion. Practical tests include sine-sweep and step testing to verify minimal dynamic error.

Why Other Options Are Wrong:
Speed of response: Addresses time to respond but not distortion.Reproducibility: Repeatability under unchanged conditions; not dynamic accuracy.Static characteristics: Pertains to steady-state sensitivity, offset, linearity.Resolution: Smallest detectable input change, not waveform truthfulness.

Common Pitfalls:
Confusing high bandwidth (speed) with fidelity; a system can be fast yet distort phases. Conversely, a slower but well-modeled system may have good fidelity within its limited band.

Final Answer:
Fidelity