Millwright Level 1 Practice Exam 2025 - Free Millwright Practice Questions and Study Guide

The selection of laser indicators as the option that is not a type of dial indicator is accurate because laser indicators operate based on a completely different principle. Dial indicators are mechanical instruments that measure small distances or variations in alignment through a dial face that displays measurements. They rely on mechanical movement to relay the measurement via a needle or pointer on a dial.

In contrast, laser indicators utilize laser beams to measure distances with high precision and are not classified as dial indicators. They do not have a dial mechanism but rather provide measurement readings based on the properties of light and reflectance.

The other choices are indeed types of dial indicators. Bottom plunger and back plunger indicators are both types that use a plunger mechanism to detect variations in height or alignment, while test indicators are specialized versions that can measure less than a thousandth of an inch with high precision. Understanding these distinctions helps clarify why laser indicators do not fit into the category of dial indicators.