CHAPTER 4 MEASUREMENT TECHNOLOGY Importance of Measurement Technology

CHAPTER 4 MEASUREMENT TECHNOLOGY

Importance of Measurement Technology Measurement technology is the foundation of manufacturing industry. For example, if a workpiece can not be accurately measured, it is impossible to know whether or not the workpiece has been correctly machined. There are many kinds of measuring tools and instruments. Learning these measuring instruments and measurement methods is an important part of this course.

Measuring Instrument (1) : Scale The scale or rule is the oldest and most commonly used measuring instrument. Steel scale is often used in industry. Scale and scriber are also used to mark lines on workpieces. Scale and scriber Scale Scribing a line

Measuring Instrument (2) : Tape Measure A tape measure is a flexible scale. Its design allows for a measure of great length to be easily carried in pocket. Tape measure

Measuring Instrument (3) : Vernier Caliper Vernier caliper gives a direct reading of the distance measured with high accuracy and precision. It provides a precision to 0. 01 mm. Vernier caliper

Measuring Instrument (3) : Vernier Caliper Inside small jaws Outside large jaws Main scale Vernier scale Diagram of Vernier caliper Depth probe

Measuring Instrument (3) : Vernier Caliper Digital caliper Dial caliper Vernier caliper

Measuring Instrument (4) : Micrometer is a device incorporating a calibrated screw widely used for precise measurement of components. It provides a precision to 0. 01 mm. Micrometer thimble with a reading of 12. 35 mm

Measuring Instrument (4) : Micrometer anvil spindle ratchet stop clamp frame Outside micrometer

Measuring Instrument (4) : Micrometer Inside micrometer Digital micrometer

Measuring Instrument (5) : Dial Indicator A dial indicator is a measuring instrument in which linear movement of a spindle is amplified by a gear train; the movement rotates a pointer over a graduated dial. Dial indicators amplify small dimensional variations so that they can easily be seen. Dial indicator

Measuring Instrument (5) : Dial Indicator The dial indicator cannot be used to measure itself alone, but must be supported on an arm from a magnetic base. The dial can then measure the difference between two works. dial indicator arm magnetic base Dial indicator Difference measured

Measuring Instrument (5) : Dial Indicator Dial indicator

Measuring Instrument (6) : Gauge Block Gauge blocks are a system for producing precision lengths. The individual gauge block is a metal block that has been precision ground and lapped to a specific thickness. In use, the blocks are stacked to make up a desired length. Gauge blocks are the main means of length standardization used by industry. Gauge block set

Measuring Instrument (7) : Feeler Gauge A feeler gauge or thickness gauge is a tool used to measure gap widths. Feeler gauges are mostly used in engineering to measure the clearance between two parts. Feeler gauge

Measuring Instrument (8) : Caliper A caliper is a device used to measure the distance between two opposite sides of an object. Outside calipers are used to measure the diameter of a shaft. The inside calipers are used to measure the diameter of a hole. Outside caliper inside caliper