Metrology & Quality Control

Metrology:Metrology is the science of measurement. In mechanical engineering, it ensures that components are manufactured with accurate dimensions, tolerances, and fits.

• Objectives of Metrology
  • Ensure accuracy and precision in measurements
  • Maintain interchangeability of parts
  • Reduce manufacturing errors
  • Standardize measurements
• Types of Measurement
  • Linear Measurement – length, diameter, thickness
  • Angular Measurement – angles, tapers
  • Comparative Measurement – comparison with standard values
• Common Measuring Instruments
  • Vernier Caliper
  • Micrometer (Outside, Inside, Depth)
  • Dial Indicator
  • Slip Gauges (Gauge Blocks)
  • Height Gauge
  • Surface Roughness Tester
• Key Terms
  • Accuracy – closeness to true value
  • Precision – repeatability of measurement
  • Tolerance – permissible variation in size
  • Least Count – smallest measurable value

Quality Control (QC):

Quality Control is the process of maintaining and improving product quality by inspecting and testing products during and after manufacturing.

• Objectives of Quality Control
  • Produce defect-free products
  • Maintain customer satisfaction
  • Reduce waste and rework
  • Ensure compliance with standards
• Stages of Quality Control
  • Incoming Inspection – raw materials
  • In-process Inspection – during manufacturing
  • Final Inspection – finished product
• Methods of Quality Control
  • Inspection (Visual, dimensional, functional)
  • Statistical Quality Control (SQC)
    1. Control Charts
    2. Sampling Techniques
  • Process Control
  • Acceptance Sampling

Difference Between Metrology & Quality Control: