How to Read a Metric Micrometer by WeldNotes.com

Summary

In this tutorial, Bob Welds teaches how to read a metric micrometer for precise measurements. He explains the parts of the micrometer, including the spindle and anvil, and focuses on reading the barrel scale marked in millimeters and half millimeters. Bob demonstrates how to interpret the thimble scale, which measures in .01 millimeters, and combines both scales for an accurate reading. He also addresses the challenge of barely visible marks and the importance of understanding the thimble's position relative to zero for accurate counting.

Takeaways

• 📏 **Micrometer Usage**: A micrometer is a tool for making precise measurements, with different types available for various applications.
• 🔍 **Metric Micrometer**: The video focuses on a metric micrometer that measures to the nearest 0.01 millimeters.
• 🔧 **Components**: The micrometer has a spindle and an anvil, where the spindle moves and the anvil remains stationary.
• 🎯 **Barrel Scale Reading**: The barrel scale is read by looking at the thimble's edge, with marks above the line indicating millimeters and those below indicating half millimeters.
• 🔢 **Millimeter Markings**: The script provides examples of how to read the barrel scale, such as identifying 12 millimeters.
• 📉 **Thimble Scale**: Each mark on the thimble represents 0.01 millimeters, allowing for readings to the nearest one hundredth of a millimeter.
• 🔄 **Combining Readings**: To get the full measurement, combine the barrel scale reading with the thimble scale reading.
• 📌 **Half Mark Consideration**: When a half mark is showing on the barrel scale, it counts as a half millimeter and should be included in the reading.
• ✏️ **Mark Counting**: When a mark is barely showing, it's important to determine if it's starting or ending to decide whether to count it.
• 🔄 **Zero Crossing**: The thimble scale's position relative to zero helps determine if a barely showing mark should be counted or not.
• 📘 **Vernier Scale**: Some micrometers have a vernier scale for even more precise measurements, which could be covered in future videos.

Q & A

What is the primary use of a micrometer?

A micrometer is used to take very precise measurements.

What different kinds of micrometers are mentioned in the script?

Inside micrometers, outside micrometers, depth micrometers, and inch micrometers are mentioned.

What does the metric micrometer in the script measure to the nearest?

The metric micrometer measures to the nearest .01 millimeters.

What are the two parts of a micrometer that open up as you turn the knurls?

The spindle and the anvil are the two parts that open up.

How do you read the barrel scale on a micrometer?

You read the barrel scale by looking at the edge of the part that turns, called the thimble.

What do the marks above the line on the barrel scale represent?

The marks above the line on the barrel scale represent millimeters.

What does the half mark on the barrel scale indicate?

The half mark on the barrel scale indicates half a millimeter.

How is the thimble scale used to measure smaller increments?

Each mark on the thimble is equal to .01 millimeters, allowing for finer measurements.

What is the reading when the barrel scale shows 12 and the thimble scale shows 0.33?

The reading would be 12.33 millimeters.

How do you handle a barely visible mark on the thimble scale?

You look at the thimble to determine if a new mark is starting or if an old mark is ending, and count it only if it's starting.

What is the trick to knowing whether to count a barely showing mark on the thimble scale?

The trick is to find which side of the zero you're working on; if you're not yet to zero, it's not yet a mark.

What additional feature might some micrometers have for even more accurate measurements?

Some micrometers might have a vernier scale for even more accurate measurements.