Quiz Of The Day

Mari kita bermain-main sejenak dengan ingatan Anda mengenai Vibration Analysis

1. Displacement is the ideal unit of measurement for performing bearing condition assessment on machines running 600 rpm or less.

a. True

b. False

2. 2. All analyzers are affected by Roll off in the same way; therefore they should all measure the same for slow speed measurements.

a. True

b. False

3. Which of the following will generate the most noise in a vibration signal?

a. Magnetically mounting the transducer

b. Integrating the signal from acceleration to displacement

c. Integrating the signal from acceleration to velocity

d. Talking while taking the measurement

4. With today's vibration analyzers it is possible to separate the signal from the noise floor even if the signal amplitude is less than the noise floor amplitude.

a. True

b. False

5. Noise filters used by many analyzers suppress the noise leaving only the remaining signal.

a. True

b. False

6. Which of the following transducer sensitivities would be best suited for a machine running 200 rpm.

a. 100 mv/g

b. 500 mv/g

c. 10 v/g

d. Seismic 7. What determines the lowest measurable frequency of an accelerometer? a. Settling Time b. Sensitivity c. Size of the transducer d. Discharge time constant 8. Which of the following is not important when collecting data on slow speed machines? a. Avoiding magnet snap b. Providing continuous sensor power c. Restricting cable movement d. Allowing proper settling time e. They are all important 9. They same overall vibration alarms can be used for a slow speed machine that are used for an 1800 rpm machine. a. True b. False 10. It is not as important to take the vibration measurement in the load zone on slow speed machines because the frequencies are lower and travel better. a. True b. False 11. The basic process of acceleration enveloping does which of the following? a. Apply filters to investigate running order faults. b. Apply band pass filters, where lower and higher order frequencies are removed. c. Apply filters to isolate high order faults. 12. Acceleration Enveloping is a desired measurement to determine which of the following machine problems? a. Misalignment. b. Unbalance. c. Bearing faults. 13. Which of the following faults represent lower order problems that would be left out of an enveloped signal? a. Unbalance and misalignment frequencies b. Gear mesh frequencies. c. Motor Bar Pass frequencies. 14. Acceleration enveloping reveals which of the following? a. Detect repetition frequencies. b. Faults that produce impacting. c. Bearing defect frequencies without interference from gear mesh frequencies. d. All of the above. 15. Acceleration envelope signals are a great aid when analyzing a multiple stage gearbox. a. True b. False 16. Why are gear mesh frequencies removed during the enveloping process? a. The amplitudes produced at running speed are too small to appear in the envelope. b. The gear meshing is a smooth process and produces little impact energy. c. None of the above. 17. What are the typical filter settings for acceleration enveloping? a. The low end filter should be above 10x rotational speed. b. The high end filter should be 6x the outer race frequency. c. The high end filter should be about 200x rotational speed. d. All of the above. 18. Will a running speed fault ever appear in the acceleration envelope reading? a. Yes. b. No. 19 What is a spectrum? a. lines of colors b. A signature (graphical display) of the vibration amplitude in the frequency domain c. Analog display of vibration amplitude in the time domain 20. What is the most important part of a spectrum? a. amplitude b. frequency c. both a & b d. none of the above 21. What does the window function do for a vibration analysis signal? a. Window function forces the signal to start and end at zero to prevent leakage b. Window functions for the signal to leak c. Window function allows the user to see out the window d. Window functions do not work 22. What is the most common window used to for vibration spectrum analysis? a. Hanning b. flat-top c. rectangular d. Kaiser 23. If an analyst suspects resonance problem with their machinery, machine foundation, frame, etc, what kind(s) of test(s) should be performed to check for this? a. Run Up b. Coast Down c. Impact Test d. All of the above e. None of the above 24. When performing an impact test to check for natural frequency, which type of window will provide the best result? a. Hanning b. flat-top c. rectangular d. Kaiser 25. The higher the number of lines of resolution specified in a spectrum, the better the accuracy provided. a. True b. False 26. What is a cepstrum? a. spectrum spelled incorrectly b. a spectrum of a spectrum c. a time waveform d. none of the above sumber : diambil dari reliability web quiz