Explore important concepts in measurement by answering questions about the static and dynamic characteristics of instruments, including accuracy, sensitivity, fidelity, and time response. This quiz is designed for learners and professionals seeking to assess and improve their understanding of instrument performance and measurement system behavior.
Which characteristic best describes the closeness of a measurement to the true value, such as when a thermometer reads exactly 100°C in boiling water at sea level?
Explanation: Accuracy is the measure of how close an instrument's reading is to the true or accepted value. Precision refers to the consistency of repeated measurements, not their closeness to the true value. Sensitivity indicates how much an instrument’s output changes in response to a change in input, not correctness. Hysteresys is incorrect here, as it refers to the difference in output for the same input based on previous input history.
When a pressure gauge shows a large output change for a small pressure input, which static characteristic is being demonstrated?
Explanation: Sensitivity measures how much output changes in response to a unit change in the input; high sensitivity means a large output change for a small input. Drift refers to a gradual change in output unrelated to the measured variable, not immediate responsiveness. Precision is about consistency, and repeatability is about the ability to give the same reading under unchanged conditions, neither of which directly measures output response magnitude to input changes.
If a temperature sensor requires several seconds to show a new correct value after a sudden temperature change, which dynamic characteristic is primarily involved?
Explanation: Response time is the dynamic characteristic describing how quickly an instrument reacts to a change in the measured variable. Stability refers to an instrument's ability to maintain its performance over time, not immediate reaction. Error denotes the deviation from the correct value, and resolution is the smallest detectable increment in measurement, neither of which directly address the timing of the instrument’s response.
Which characteristic is illustrated when a weighing scale gives a slightly different reading for the same object depending on whether its load is increasing or decreasing?
Explanation: Hysteresis refers to the difference in output of an instrument for the same input value, depending on the direction of input change (increasing or decreasing load). Loading error is an error introduced when the measuring instrument disturbs the measured system, which is not the scenario described. Resolution is about the smallest detectable change, and sensitivity is about output change for a unit input change. Only hysteresis explains differing values based on loading direction.
When an instrument faithfully reproduces rapid variations in input without distortion, such as a speaker system tracking fast-changing audio signals, which dynamic characteristic is most relevant?
Explanation: Fidelity is the dynamic characteristic that indicates how accurately an instrument can reproduce the time-varying nature of an input signal. Zero drift is unrelated, as it describes changes in output at zero input over time. Nonlinearity refers to deviation from a straight-line response between input and output, not the faithfulness to changes. Span is the range of measurement and is not about the ability to track rapid input variations.