Types of Gauges

 - Gauges are the inspection tools with or without scale which are used to check product dimensions with reference to it's maximum and minimum acceptable limit. 

 - Gauges perform an essential services in any scheme of quality production on an interchangeable basis.

 - Gauges are divided in two categories. 1) Standard Gauge 2) Non-Standard gauge

1) Standard Gauge:

 - If the gauge is an exact copy of mating part of the component to be checked then it is called Standard gauges.

 - E.g. Ring gauge, Plug gauge, etc..

2) Non-Standard Gauge:

 - It has no accurate standard for measurement but it is made from some relative reference is called non-standard gauge.

 - E.g. Templates, Receiving gauges, etc..

Advantages of Gauges

 - Faster checking regarding whether product is within it's specified limit or not.

 - Less dependence on operator skill and hence result are not getting affected by operator judgement.

 - More than one dimension of product can be check at a time as well as properties like roundness, taper etc.

 - More economical than measuring instruments.

Examples of Gauges:

1) Plug gauge

 - It is used for checking of holes is ok or not ok as per plug gauge specification

 - In plug gauge Go is lower limit and No-Go is higher limit of hole

2) Snap gauge & Ring gauge

 - This gauge used to check the external dimensions of the product like diameter, thickness etc. 

 - Snap gauge is use for cylindrical as well as non cylindrical parts whereas Ring gauge is used only for cylindrical parts.

 - In this Go is upper limit and No-Go is lower limit of part.

3) Feeler

 - Feeler gauges are used for checking clearance between mating surfaces.

4) Radius gauge

 - Radius gauge are used to check the radius of curvature of convex and concave surface ranging from 1 to 25 mm.

 - This gauges are made in sets of thin plates curved to different radius at the end.

 - Each set of gauge consist of 16 convex and 16 concave blades.

5) Screw/Thread Pitch gauge

 - Screw pitch gauge are used to check the pitch of the screw threads. They consist of flat blades which are cut out to a given pitch.

 - Each blade is engraved with the pitch or number of threads per inch.

6) Slip gauges (Gauge Block)

 - Slip gauges were first developed by Johnson, and also called as 'Johnson Gauge Blocks'. Slip gauge are rectangular blocks of steel having a cross-section of about 32 mm x 9 mm.

 - If two blocks are twisted together with certain pressure, it will be found that due to molecular attraction and atmospheric pressure they will adhere to each other quite firmly. This process is known as wringing process. This Process is very useful to make a required size by assemble several gauge blocks.

7) Scale

 - Scale is used to measure lengths and other geometrical parameter's. They can be a single steel rule or flexible tape type.

8) Vernier caliper

 - It is used to measure small distance with high accuracy.

 - It has two jaws to measure outside and inside dimension of object.

 - It can be analog and digital type of instrument and more accurate than scale.

9) Micrometer

 - It is fine precise tool used to measure small distance and it is more accurate than Vernier caliper.

10) Angle plate (Try Square)

 - it is a right angle plate or tool used to measure the true right angle between two objects when joined together.

Also Visit Types of Measuring Instruments