Measuring Techniques with Hardness Tester and Calipers

Aug 28, 2024

Lecture Notes: Using Shore D Polymer Hardness Tester, Calipers, and Micrometer

Introduction

  • Overview of using Shore D polymer hardness tester, calipers, and micrometer.
  • Importance of recording raw data in a lab book before entering it into a spreadsheet.

Shore D Polymer Hardness Tester

  • Shore: Manufacturer
  • Scale D: Used for harder polymers (e.g., Shore A for softer polymers).
  • Procedure:
    • Place the tester's indenter on the polymer and press down.
    • Perform the test with a partner; one person presses while the other reads the measurement.
    • Record the measurement in the lab book.
    • Repeat the process to ensure accuracy.

Using Calipers

  • Preparation:
    • Gently bring the jaws together and zero out the calipers.
    • Example provided is already zeroed.
  • Measuring Process:
    • Outer Diameter:
      • Use one side of the calipers.
      • Measure at multiple locations to check for irregularities.
    • Inner Diameter:
      • Use the other end of the calipers.
      • Avoid using parts beyond the measurement surface to ensure accuracy.
    • Depth Measurement:
      • Place edge of calipers on cavity edge and lower depth gauge.
      • Record units consistently.
      • Avoid measuring at indents.
  • Post-Measurement:
    • Turn off calipers to save battery.

Using a Micrometer

  • Storage:
    • Ensure jaws are slightly apart to prevent jamming.
  • Measurement Procedure:
    • Gently close the jaws and zero it out.
    • Set to inches for consistency.
    • Measuring Wires:
      • Larger diameter wire:
        • Use a partner to stabilize wire.
        • Measure gently to grip wire for accuracy.
        • Example reading: 0.0217 inches.
        • Measure three times at different points.
      • Record reference letter associated with wire.
      • Smaller diameter wire:
        • Handle carefully to prevent slipping.
  • Post-Measurement:
    • Ensure jaws are slightly apart before storing the micrometer.