How to Read a Vernier Caliper

Introduction

• Vernier calipers are precision measuring instruments used to measure dimensions.
• They have two sets of graduations: the main scale and the vernier scale.

Main Scale

• Found on inch calipers.
• Marked in intervals of 0.025 inches.
• Read directly by locating the last graduation passed by the zero mark on the sliding jaw.
  • Example: If the zero mark passes the number 5 and two more hash marks, the reading is 0.55 inches.

Vernier Scale

• Located on the sliding jaw.
• Typically has 25 graduations on modern inch vernier calipers.
• Provides a final graduation of 0.001 inches.

Reading Process

Step 1: Reading the Main Scale

1. Look at the zero mark on the sliding scale.
2. Identify the last graduation it passed on the main scale.
   • Example: 0.55 inches.

Step 2: Reading the Vernier Scale

1. Observe how the lines on the vernier scale match up with the lines on the main scale.
2. Only one line will align correctly.
   • Example: If the 15 on the vernier scale matches, the reading is 0.015 inches.

Final Measurement Calculation

• Add the readings from the main scale and vernier scale.
  • Example: 0.550 inches (main scale) + 0.015 inches (vernier scale) = 0.565 inches.

Conclusion

• The total measurement is the sum of the main scale and vernier scale readings.
• Practice will improve speed and accuracy in reading vernier calipers.