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Measurement Uncertainty Quiz

Test yourself with 20 multiple choice questions. Check your answers to get a score and an explanation for every question.

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Measurement Uncertainty Quiz: 20 Questions

Choose one answer for each question, then press Check answers. Explanations appear after checking.

1. Calibration error of 5.03 bar at 5.00 bar on a 0 to 10 bar span is:

Answer: 0.3 % of span. 0.03 ÷ 10 × 100. Learn more: Accuracy

2. Precision describes:

Answer: Closeness of repeated readings to each other. Accuracy is closeness to true value. Learn more: Precision

3. Repeatability is measured under:

Answer: The same conditions and short time. Changed conditions give reproducibility. Learn more: Repeatability

4. Hysteresis is found by:

Answer: Comparing upscale and downscale readings. Direction dependent difference. Learn more: Hysteresis

5. Combined standard uncertainty is calculated by:

Answer: Root sum of squares of standard uncertainties. GUM method for independent sources. Learn more: Measurement Uncertainty
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6. k = 2 gives a coverage probability of about:

Answer: 95 %. For a normal distribution. Learn more: Coverage Factor

7. A rectangular distribution of half width a has standard uncertainty:

Answer: a ÷ √3. Type B evaluation. Learn more: Type A and Type B Uncertainty

8. Type A uncertainty of a mean is:

Answer: s ÷ √n. Standard deviation of the mean. Learn more: Type A and Type B Uncertainty

9. A commonly required minimum TUR is:

Answer: 4:1. Long standing industry rule. Learn more: Test Uncertainty Ratio

10. Tolerance ± 0.25 %, calibration uncertainty ± 0.05 % gives TUR:

Answer: 5:1. 0.25 ÷ 0.05. Learn more: Test Uncertainty Ratio
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11. A guard band:

Answer: Tightens acceptance limits by allowing for uncertainty. Reduces false acceptance risk. Learn more: Guard Band

12. Traceability requires:

Answer: An unbroken chain of calibrations with stated uncertainty. Up to national standards and SI units. Learn more: Traceability

13. As found readings are taken:

Answer: Before any adjustment. They show performance in service. Learn more: As Found and As Left

14. A five point calibration uses:

Answer: 0, 25, 50, 75, 100 % of range. Usually rising and falling. Learn more: Five Point Calibration

15. Total probable error combines errors by:

Answer: Root sum of squares. For independent errors. Learn more: Total Probable Error
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16. 0.065 %, 0.10 % and 0.05 % combine to a TPE of about:

Answer: 0.13 %. √(0.065² + 0.1² + 0.05²). Learn more: Total Probable Error

17. A deadweight tester generates pressure from:

Answer: Mass × local gravity ÷ piston area. Primary pressure standard. Learn more: Deadweight Tester

18. Why correct a deadweight tester for local gravity?

Answer: Weight depends on local g. g varies about 0.5 % over the earth. Learn more: Local Gravity

19. The standard for calibration lab competence is:

Answer: ISO/IEC 17025. Accreditation in India is by NABL. Learn more: ISO/IEC 17025

20. Calibration correction equals:

Answer: True value − reading. Correction is the negative of error. Learn more: Calibration Correction
0 of 20 answered
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About this Quiz

20 multiple choice questions on measurement uncertainty, the kind asked in instrumentation interviews, technician exams and plant training. Each answer comes with a short explanation, so the quiz works as a revision sheet too.

Show answer key
  1. 0.3 % of span: 0.03 ÷ 10 × 100. Learn more: Accuracy
  2. Closeness of repeated readings to each other: Accuracy is closeness to true value. Learn more: Precision
  3. The same conditions and short time: Changed conditions give reproducibility. Learn more: Repeatability
  4. Comparing upscale and downscale readings: Direction dependent difference. Learn more: Hysteresis
  5. Root sum of squares of standard uncertainties: GUM method for independent sources. Learn more: Measurement Uncertainty
  6. 95 %: For a normal distribution. Learn more: Coverage Factor
  7. a ÷ √3: Type B evaluation. Learn more: Type A and Type B Uncertainty
  8. s ÷ √n: Standard deviation of the mean. Learn more: Type A and Type B Uncertainty
  9. 4:1: Long standing industry rule. Learn more: Test Uncertainty Ratio
  10. 5:1: 0.25 ÷ 0.05. Learn more: Test Uncertainty Ratio
  11. Tightens acceptance limits by allowing for uncertainty: Reduces false acceptance risk. Learn more: Guard Band
  12. An unbroken chain of calibrations with stated uncertainty: Up to national standards and SI units. Learn more: Traceability
  13. Before any adjustment: They show performance in service. Learn more: As Found and As Left
  14. 0, 25, 50, 75, 100 % of range: Usually rising and falling. Learn more: Five Point Calibration
  15. Root sum of squares: For independent errors. Learn more: Total Probable Error
  16. 0.13 %: √(0.065² + 0.1² + 0.05²). Learn more: Total Probable Error
  17. Mass × local gravity ÷ piston area: Primary pressure standard. Learn more: Deadweight Tester
  18. Weight depends on local g: g varies about 0.5 % over the earth. Learn more: Local Gravity
  19. ISO/IEC 17025: Accreditation in India is by NABL. Learn more: ISO/IEC 17025
  20. True value − reading: Correction is the negative of error. Learn more: Calibration Correction
Tip: take the quiz before an interview, note the questions you missed and read the linked article for those topics.
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Frequently Asked Questions

Is this quiz free?

Yes. No sign up is needed and you can retake it as often as you like.

Are the answers explained?

Yes. After you check your answers, each question shows the correct answer and a short explanation.

Where can I find more questions?

See the Interview Q&A section of instrumentationblog.in and the linked article below.

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