Measuring Tools and Techniques

Measuring Tools in the Pipe Industry

Imperial vs. Metric Systems

  • The inside micrometer is primarily used within the imperial system, making it less common compared to the outside micrometer and vernier caliper.
  • Outside micrometers and vernier calipers are more commonly used and known, especially by those who completed apprenticeships in the past.

Tools

  • Vernier caliper.
  • Outside micrometer.
  • Inside micrometer (imperial system).
  • Outside depth micrometer

Practical Measuring

  • Physical demonstrations/measurements will be conducted to enhance understanding.
  • Students are encouraged to search online and read about proper reading techniques for measuring tools.
  • Questions are encouraged to address any difficulties encountered during self-study.

Personal Tools

  • Personal tools should not be brought in due to potential loss or damage, especially expensive brands like Mitutoyo (Japanese made).
  • Instead of bringing personal tools, students can create short videos explaining their use and readings.
  • Video projects can be a group effort to research and explain the inside micrometer, showcasing readings and extension usage.
  • If access to tools is available, creating a video of their use is preferred over bringing the physical tools.

Steel Ruler Selection

  • Factors influencing the decision when purchasing a steel ruler:
    • Brand.
    • Quality.
    • Durability.
    • Metric system.
    • Accuracy.
    • Pricing.
    • Length.

Key Considerations for Steel Rulers

  • Quality and Make: Focus on quality and make rather than just aesthetics.
  • Durability and Strength: Account for durability and strenth.
  • Metric System: A metric system is also important to consider.
  • Accuracy: Prioritize accuracy as a critical factor.
  • Length: Different lengths are available based on what it is needed for.

Dissecting Price Factors

  • The material influences quality, differentiating the quality of a ruler from clothing or food.
  • Quality is linked to:
    • Type of material.
    • Measurements (metric/imperial).
    • Length.
    • Brands.
    • Accuracy.

Material Considerations

  • The intended use of the steel ruler determines the necessary material properties.
    • For measuring on cold surfaces, extreme durability and strength may not be necessary.
    • Alternatives like aluminum or plastic rulers are options.

Importance of Accuracy

  • Accuracy is essential:
    • Inaccurate rulers can affect drawings.

Ruler Types

  • Various ruler types exist for different applications:
    • Standard rulers in various lengths.
    • Angle rulers.

Measurement Systems

  • Rulers come in different measurement systems:
    • Imperial (inches).
    • Metric (centimeters, millimeters).
    • Combined systems.

Quality vs. Material

  • Material is a component of overall quality.

Key Factors in Ruler Selection

  • Type of Material.
  • Length.
  • Accuracy.
  • Measurement system.
  • Price.

Loose Rivets

  • The tip of some rulers are loosely riveted for flexibility which allows movement and accuracy.
  • Even with a small gap at the starting point, the design maintains measurement accuracy.
  • This design prevents lifting or retraction, which could lead to false readings.

Care of Measuring Tools

  • Proper storage is essential.
  • Cleaning must be done carefully rather than just tossing the tool into a box because there are many ways to clean a measuring tool

Cleaning Process

  • Use a microfiber cloth.
  • It needs to be finely made or else it won't work.

Component Knowledge

  • Understand the parts of the measuring tool to fully clean it.
    • For micrometers, the thimble and barrel can be unscrewed for cleaning.

Cleaning Agents

  • Petrol can be used for cleaning but requires re-greasing of the threads with a fine type of threaded grease.

Impact of Dirt

  • Dirt on threads can affect measurement accuracy.

Anvil and Spindle

  • Protect the anvil and spindle surfaces.
  • Avoid cuts or abrasions on these surfaces to maintain accurate measurements.
  • Any burs will affect the measurements of the object.

Reading Micrometers

  • Some tools the solid numbers are on top, while others will have them at the bottom.
  • Solid numbers are similar to rulers, going from 1 to 25.
  • Every line in between each solid number is a half millimeter.
  • 0. 5, 1.5, 2.5, 3.5 and 4.5 are examples

Equator or Zero Line

  • The zero line:
    • Above = 4.00
    • Below = 0.5

Barrel and Thimble

  • Barrel + Thimble = 34 - Final measurement

Constant and Variable

  • Variable:
    • Changes
    • Can go down to a factor of 0.
  • Constant:
    • 0.01 all the way to 0.49

Thimble Divisions

  • A micrometer is divided into 30 divisions, but this is only half accurate.
  • 0 - 0.49 will be the accurate answer because it will return to zero after 0.49.

Thimble Line

  • The thimble line shows 0.5, crucial for precise measurement.

Micrometer Types

  • Outside Micrometer
    • Out = 0-25
  • Inside Micrometer
    • In = 0-13

Inside Micrometer Usage

  • Accompanied by a spacer and extension bar.
  • The spacer typically has a length of 12 millimeters.
  • The Inside micrometer goes up to 13 not 25.

Extension Bar Increments

  • Increment of 25 which starts from 0-25, 25-50, 50-75, 75-100 and so on.

External vs. Internal Measurements

  • Outside micrometers increase in size; inside micrometers use extension bars.
  • External damages are more commonly found than internal damages.
  • Internal damages are more frequently found due to the crushing of rocks.

Practical Example

  • Measuring train track wheels with a large micrometer.
  • One person tightens while the other alters for reading the measurement.