What is the total caliper measurement equal to?

• A. Scale reading + dial reading
• B. Dial reading + scale reading
• C. Scale reading
• D. Dial reading

Answer: (A)

Measuring with a caliper blends two readings to form the full length: the main scale and the dial. The total measurement is the sum of the scale reading and the dial reading because the main scale provides the larger units and the dial gives the finer fractional part. For example, if the main scale shows 25 mm and the dial indicates 0.6 mm, the total is 25.6 mm. You add the two parts to get the final dimension; taking only the scale reading or only the dial reading misses part of the measurement, so they aren’t sufficient on their own.