PRECISION MEASURING INSTRUMENTS

Other Chapters

• Q1: What are Precision Measuring Instruments?
  Ans: Precision measuring instruments are tools used to measure dimensions with very high accuracy and small least count.
• Q2: Name some Precision Measuring Instruments.
  Ans: Some precision measuring instruments are:

  • ➔ Vernier Caliper
  • ➔ Micrometer Screw Gauge
  • ➔ Vernier Height Gauge
  • ➔ Dial Indicator
• Q3: What is a Vernier Height Gauge?
  Ans: A Vernier height gauge is a precision instrument used to measure and mark vertical heights from a surface plate.
• Q4: Name some parts of Vernier Height Gauge.
  Ans: Parts are:

  • ➔ Base
  • ➔ Main scale
  • ➔ Vernier scale
  • ➔ Sliding carriage
  • ➔ Measuring jaw/scriber
  • ➔ Fine adjustment screw
• Q5: State the working principle of Vernier Height Gauge.
  Ans: It works on the vernier scale principle.
  The height is measured by moving the slider along the main scale and reading vernier scale values for precision.
• Q6: What is the Least Count of a Vernier Height Gauge?
  Ans: The least count is usually 0.02 mm.
• Q7: State some precautionary measures while using a Vernier Height Gauge.
  Ans: Precautions are:

  • ➔ Keep surface plate clean
  • ➔ Ensure proper zero setting
  • ➔ Do not apply excessive force
  • ➔ Handle carefully to avoid damage
• Q8: State the uses of Vernier Height Gauge.
  Ans: Uses are:

  • ➔ Measuring vertical heights
  • ➔ Marking layout lines
  • ➔ Checking dimensions on surface plate
• Q9: What is a Vernier Depth Gauge?
  Ans: A Vernier depth gauge is a precision instrument used to measure the depth of holes, slots, and recesses.
• Q10: Name some parts of Vernier Depth Gauge.
  Ans: Parts are:

  • ➔ Main scale
  • ➔ Vernier scale
  • ➔ Base
  • ➔ Depth rod
  • ➔ Lock screw
• Q11: State the working principle of Vernier Depth Gauge.
  Ans: It works on the vernier principle.
  The depth rod moves into the hole and readings are taken from main and vernier scales.
• Q12: What is the Least Count of a Vernier Depth Gauge?
  Ans: The least count is usually 0.02 mm.
• Q13: State some precautionary measures while using a Vernier Depth Gauge.
  Ans: Precautions are:

  • ➔ Keep base flat on surface
  • ➔ Avoid tilting during measurement
  • ➔ Check zero error
  • ➔ Handle carefully
• Q14: State the uses of Vernier Depth Gauge.
  Ans: Uses are:

  • ➔ Measuring depth of holes
  • ➔ Measuring slots and grooves
  • ➔ Inspection work
• Q15: What is an Inside Micrometer?
  Ans: An inside micrometer is a precision instrument used to measure internal dimensions like bore diameters and inside widths.
• Q16: Name some parts of an Inside Micrometer.
  Ans: Parts are:

  • ➔ Measuring rods
  • ➔ Spindle
  • ➔ Thimble
  • ➔ Ratchet stop
  • ➔ Lock nut
• Q17: State the types of an Inside Micrometer.
  Ans: Types are:

  • ➔ Rod type inside micrometer
  • ➔ Caliper type inside micrometer
• Q18: State the working principle of an Inside Micrometer.
  Ans: It works on the screw and nut principle.
  Rotational movement is converted into linear movement to measure internal dimensions accurately.
• Q19: What is the Least Count of an Inside Micrometer?
  Ans: The least count is usually 0.01 mm.
• Q20: State some precautionary measures while using an Inside Micrometer.
  Ans: Precautions are:

  • ➔ Do not apply excess force
  • ➔ Clean measuring surfaces
  • ➔ Check zero error
  • ➔ Handle carefully
• Q21: State the uses of an Inside Micrometer.
  Ans: Uses are:

  • ➔ Measuring internal diameters
  • ➔ Measuring bore sizes
  • ➔ Inspection of machine parts
• Q22: What is a Depth Micrometer?
  Ans: A depth micrometer is a precision measuring instrument used to measure the depth of holes, slots, grooves, and recesses accurately.
• Q23: Name some parts of a Depth Micrometer.
  Ans: Parts are:

  • ➔ Base plate
  • ➔ Spindle
  • ➔ Thimble
  • ➔ Sleeve (barrel)
  • ➔ Ratchet stop
  • ➔ Lock nut
• Q24: State the working principle of a Depth Micrometer.
  Ans: It works on the screw and nut principle.
  The spindle moves linearly when rotated, allowing precise depth measurement.
• Q25: What is the Least Count of a Depth Micrometer?
  Ans: The least count is usually 0.01 mm.
• Q26: State some precautionary measures while using a Depth Micrometer.
  Ans: Precautions are:

  • ➔ Keep base flat on surface
  • ➔ Do not tilt during measurement
  • ➔ Clean before use
  • ➔ Check zero error
• Q27: State the uses of a Depth Micrometer.
  Ans: Uses are:

  • ➔ Measuring depth of holes
  • ➔ Measuring slots and grooves
  • ➔ Inspection of machined parts
• Q28: What is a Thread Micrometer?
  Ans: A thread micrometer is a precision instrument used to measure the pitch diameter of screw threads accurately.
• Q29: Name some parts of a Thread Micrometer.
  Ans: Parts are:

  • ➔ Frame
  • ➔ Spindle
  • ➔ Anvil (threaded/V-shaped)
  • ➔ Thimble
  • ➔ Ratchet stop
• Q30: State the working principle of a Thread Micrometer.
  Ans: It works on the screw and nut principle.
  Special V-shaped anvils measure the pitch diameter of threads accurately.
• Q31: What is the Least Count of a Thread Micrometer?
  Ans: The least count is usually 0.01 mm.
• Q32: State some precautionary measures while using a Thread Micrometer.
  Ans: Precautions are:

  • ➔ Handle carefully
  • ➔ Do not apply excess force
  • ➔ Clean thread surfaces before use
  • ➔ Check zero error
• Q33: State the uses of a Thread Micrometer.
  Ans: Uses are:

  • ➔ Measuring pitch diameter of threads
  • ➔ Inspection of screws and bolts
  • ➔ Quality control in manufacturing
• Q34: State the calibrations of a Micrometer.
  Ans: Calibration of a micrometer means checking and adjusting its accuracy using standard gauge blocks to ensure correct readings.
• Q35: State the adjustments of a Micrometer.
  Ans: Adjustments of a micrometer include:

  • ➔ Zero adjustment
  • ➔ Sleeve alignment adjustment
  • ➔ Ratchet pressure adjustment
• Q36: What is a Hot Gauge Micrometer?
  Ans: A hot gauge micrometer is a special micrometer used to measure dimensions of hot or heated workpieces with temperature compensation.
• Q37: What is a Vernier Micrometer?
  Ans: A vernier micrometer is a micrometer fitted with a vernier scale to increase measurement accuracy beyond standard micrometer readings.
• Q38: What is a Gear Tooth Vernier?
  Ans: A gear tooth vernier is a precision instrument used to measure the tooth thickness and chordal height of gear teeth.