AIT Measurement Tools 2 — Questions and Answers
Question 1: When using a micrometer, what does one full revolution of the thimble equal on a standard inch micrometer?
- 0.010 inch
- 0.025 inch (Correct answer)
- 0.001 inch
- 0.100 inch
Correct answer: 0.025 inch
One full revolution of the thimble on a standard inch micrometer advances the spindle 0.025 inch.
Question 2: Which type of square is used to check both 45-degree and 90-degree angles?
- Try square
- Combination square (Correct answer)
- Framing square
- Speed square
Correct answer: Combination square
A combination square has a sliding head that can be set to check both 45-degree and 90-degree angles.
Question 3: A dial indicator reads 0.035 inch. If the needle moves 2 more full revolutions (each revolution = 0.100 inch), what is the total reading?
- 0.235 inch (Correct answer)
- 0.235 inch
- 0.135 inch
- 0.235 inch
Correct answer: 0.235 inch
Two full revolutions equal 0.200 inch added to the initial 0.035 inch gives 0.235 inch.
Question 4: What tool is best suited for measuring the inside diameter of a large pipe with a diameter over 6 inches?
- Inside micrometer (Correct answer)
- Vernier caliper
- Telescoping gauge with outside micrometer
- Feeler gauge
Correct answer: Inside micrometer
An inside micrometer (tubular or rod type) is designed for measuring large internal diameters directly.
Question 5: What is the purpose of a surface plate in precision measurement?
- To grind workpieces flat
- To provide a known flat reference surface for layout and inspection (Correct answer)
- To measure surface roughness
- To hold workpieces during machining
Correct answer: To provide a known flat reference surface for layout and inspection
A surface plate provides an accurate flat reference datum for layout, inspection, and measurement work.
Question 6: Which instrument measures angles in degrees, minutes, and seconds with the highest precision?
- Protractor
- Bevel gauge
- Optical vernier bevel protractor (Correct answer)
- Combination square
Correct answer: Optical vernier bevel protractor
An optical vernier bevel protractor can resolve angles to 5 minutes (1/12 degree) or finer with the vernier scale.
Question 7: What does 'runout' measure when using a dial indicator on a rotating shaft?
- Surface hardness
- The total variation in the surface position relative to the axis of rotation (Correct answer)
- Thread pitch diameter
- Shaft length
Correct answer: The total variation in the surface position relative to the axis of rotation
Runout is the total indicator reading (TIR) showing how much a surface deviates from true rotation about an axis.
AIT Measurement Tools 2
When using a micrometer, what does one full revolution of the thimble equal on a standard inch micrometer?