Dial Test Indicator

Indicator (Distance Amplifying Instrument)

In various contexts of science, technology, and manufacturing (such as machining, fabricating, and additive manufacturing), an indicator is any of various instruments used to accurately measure small distances and angles, and amplify them to make them more obvious. The name comes from the concept of indicating to the user that which their naked eye cannot discern; such as the presence, or exact quantity, of some small distance (for example, a small height difference between two flat surfaces, a slight lack of concentricity between two cylinders, or other small physical deviations).

Many indicators have a dial display, in which a needle points to graduations in a circular array around the dial. Such indicators, of which there are several types, therefore are often called dial indicators.

Non-dial types of indicators include mechanical devices with cantilevered pointers and electronic devices with digital displays.

Indicators may be used to check the variation in tolerance during the inspection process of a machined part, measure the deflection of a beam or ring under laboratory conditions, as well as many other situations where a small measurement needs to be registered or indicated. Dial indicators typically measure ranges from 0.25mm to 300mm (0.015in to 12.0in), with graduations of 0.001mm to 0.01mm (metric) or 0.00005in to 0.001in (imperial/customary).

Various names are used for indicators of different types and purposes, including dial gauge, clock, probe indicator, pointer, test indicator, dial test indicator, drop indicator, plunger indicator, and others

Try Our Interactive DTI

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Applications

  • To check for run-out when fitting a new disc to an automotive disc brake. Run-out can rapidly ruin the disc if it exceeds the specified tolerance (typically 0.05mm or less).
  • In a quality environment to check for consistency and accuracy in the manufacturing process.
  • On the workshop floor to initially set up or calibrate a machine, prior to a production run.
  • By toolmakers  in the process of manufacturing precision tooling.
  • In metal engineering workshops, where a typical application is the centering of a lathe’s workpiece in a four jaw chuck. The DTI is used to indicate the run out (the misalignment between the workpiece’s axis of rotational symmetry and the axis of rotation of the spindle) of the workpiece, with the ultimate aim of reducing it to a suitably small range using small chuck jaw adjustments.
  • In areas other than manufacturing where accurate measurements need to be recorded – Shaft Alignment & Run-out