Which of the following is a common cause of "Systematic Error" in measurement?

• A. Environmental changes during measurement
• B. Incorrect calibration of the instrument
• C. Operator fatigue during operations
• D. Time variations between measurements

Answer: (B)

A common cause of "Systematic Error" in measurement pertains to the effects that consistently skew results in a particular direction. Incorrect calibration of the instrument is a prime example of this type of error. When an instrument is not calibrated properly, it can produce results that deviate from the true value in a consistent manner. This means if an instrument measures something incorrectly due to a calibration issue, it will always give a similar level of incorrectness whenever that measurement is taken under the same conditions, leading to a systematic bias in the results.

In contrast, environmental changes during measurement can introduce variability but do not necessarily lead to systematic bias in the same way. Similarly, operator fatigue can result in inconsistencies or random errors due to variations in performance but does not consistently affect measurements in one direction. Time variations between measurements may lead to differences based on changes over time, but they are not inherently linked to systematic errors unless they are tied to a consistent, reproducible fault in the measurement system itself.