How to Read Calipers On Micrometers

Inside/Outside caliper micrometer

A caliper micrometer is used when a measurement must be precise. Although it can be used to measure anything that will fit inside the calipers, its greatest utility comes in measuring those or odd-shaped objects. Basically, a caliper micrometer works by opening or closing the calipers until they touch the object and then reading the measurement. Most designs have thumb wheels or other devices to adjust the calipers; some have a separate device to fine-tune the measurement.

Instructions

1. Find the "0" on the sliding Vernier scale. Read the number from the fixed scale that it points to. If it's between two values, read the lower value.

2. Find the line on the Vernier scale that aligns perfectly with another line on the fixed scale. If no lines are perfectly aligned, find the one that's closest. Read the number on the Vernier scale for this line.

3. 

   Combine the two readings to get the measured value. In the photo, the fixed reading is 3 mm and the Vernier reading is 0.58 mm, so the combined measurement is 3.58 mm.