In order to read the scales on the micrometers in the illustration, follow these steps:
1. Identify the main scale: The main scale is the long scale located on the barrel of the micrometer. It is usually divided into inches or millimeters.
2. Determine the value of the main scale divisions: Look for the numbers or markings on the main scale that indicate the measurement divisions. For example, if the main scale is in inches, each division might represent 0.1 inch.
3. Read the main scale value: Locate the point on the main scale that aligns with the reference line or zero line on the thimble (the rotating barrel). This point indicates the whole number measurement on the main scale.
4. Identify the thimble scale: The thimble scale is the smaller scale located on the rotating barrel of the micrometer. It is divided into smaller divisions.
5. Determine the value of the thimble scale divisions: Look for the numbers or markings on the thimble scale that indicate the measurement divisions. Each division on the thimble scale represents a fraction of the main scale division. For example, if each main scale division is 0.1 inch, each thimble scale division might represent 0.025 inch.
6. Read the thimble scale value: Locate the point on the thimble scale that aligns with the reference line on the barrel. This point indicates the fractional measurement on the thimble scale.
7. Calculate the total measurement: Add the whole number measurement from the main scale to the fractional measurement from the thimble scale to get the total measurement. For example, if the main scale reads 0.5 inch and the thimble scale reads 0.025 inch, the total measurement would be 0.525 inch.
Remember to record your answers in the appropriate blanks based on the readings you obtain from the main scale and thimble scale.