AIT Measurement Tools 3 — Questions and Answers
Question 1: A steel rule graduated in 1/64-inch increments is used to measure a part. What is the smallest increment that can be directly read?
- 0.010 inch
- 0.015625 inch (Correct answer)
- 0.0625 inch
- 0.03125 inch
Correct answer: 0.015625 inch
1/64 inch equals 0.015625 inch, which is the finest graduation on that rule.
Question 2: When a feeler gauge blade drags with slight resistance when pulled from between two surfaces, this indicates the gap equals what?
- The blade thickness minus 0.001 inch
- The nominal thickness of that blade (Correct answer)
- The sum of all blades used
- Zero clearance
Correct answer: The nominal thickness of that blade
A slight drag means the gap matches the nominal thickness of the feeler blade being used.
Question 3: What is the function of the datum line on a vernier caliper scale?
- It marks the maximum measurement capacity
- It is the reference line from which both main scale and vernier readings are taken (Correct answer)
- It shows the zero error correction
- It indicates the jaw gap in metric units
Correct answer: It is the reference line from which both main scale and vernier readings are taken
The datum (index) line on the vernier scale aligns with the main scale to provide the reference for reading.
Question 4: In pipe fitting, a pipe wrap or circumference tape is used primarily to:
- Measure wall thickness
- Find the center for a cut by wrapping around the pipe circumference (Correct answer)
- Measure thread pitch
- Check pipe roundness
Correct answer: Find the center for a cut by wrapping around the pipe circumference
A pipe wrap (wraparound) provides a straight reference line around a pipe's circumference to mark a square cut line.
Question 5: A bore gauge is set using an outside micrometer before use. Why?
- To calibrate the micrometer
- To set the bore gauge to a known dimension so it reads deviation from that size (Correct answer)
- To check the bore gauge for wear
- To convert metric readings to inches
Correct answer: To set the bore gauge to a known dimension so it reads deviation from that size
Setting the bore gauge against a micrometer at the nominal size allows it to show plus or minus deviation from that dimension.
Question 6: Which measurement technique uses a known standard block and a dial indicator to compare an unknown dimension?
- Direct measurement
- Comparative (transfer) measurement (Correct answer)
- Indirect measurement
- Coordinate measurement
Correct answer: Comparative (transfer) measurement
Comparative measurement involves zeroing an indicator on a known standard and reading the deviation on the unknown part.
Question 7: What is the correct way to store a micrometer when not in use?
- With the spindle fully closed against the anvil
- With a small gap between spindle and anvil, and in its case (Correct answer)
- Hanging on a hook by the frame
- Submerged in cutting oil
Correct answer: With a small gap between spindle and anvil, and in its case
Leaving a small gap prevents thermal expansion from damaging the measuring faces, and the case protects from dust and damage.
AIT Measurement Tools 3
A steel rule graduated in 1/64-inch increments is used to measure a part.
What is the smallest increment that can be directly read?