What is a dial indicator?

A dial indicator, sometimes referred to as a dial gauge, is a precision measurement tool commonly used in manufacturing and engineering applications. The device typically consists of a movable plunger or probe that can be inserted into a part or assembly to take measurements, and a dial face that displays those measurements in units of distance or other units of measurement.

Dial indicators can be used for a variety of purposes, including:

• Measuring the distance between two surfaces or components, such as a gap or clearance
• Checking the position or runout of rotating shafts or gears
• Verifying the accuracy of machine tool positioning and alignment
• Monitoring changes in length or dimensions over time, such as during thermal expansion or contraction

The accuracy of a dial indicator is typically expressed in terms of resolution (the smallest increment that can be measured), range (the maximum distance that can be measured), and repeatability (the ability to consistently reproduce a measurement). Dial indicators may be mechanical, digital, or hybrid (combining mechanical and electronic elements), and may incorporate features such as data output for automated measurement and analysis. Some common brands of dial indicators include Mitutoyo, Starrett, and Fowler.