02-16-2016, 03:12 PM
The small gauge on the left is normally referred to as a DTI. (Dial TEST Indicator.) Again, that is the type used for fine / extremely accurate measurements. Because of the increased resolution built into those indicators, there is a definite increase in the cost to manufacture them as Mayhem noted above.
The larger gauge on the right is what most people think of as a DI. Just plain old "Dial Indicator". Very common and import versions can be purchased very cheaply. High quality name brand versions that are built to a higher standard can be quite costly as well. "You get what you pay for" as they say.
To add to Tom's point about measuring inside of holes or slots with a DTI, I will add that you can purchase accessory attachments for a standard dial indicator (DI) that will allow you to perform the same task. Just not quite as accurately as using a DTI.
![[Image: marcator--ansi_accessories--pic--320x240.jpg]](http://www.mahr.com/images/products/Metrology/marcator/systems/ansi_dial_indicators/marcator--ansi_accessories--pic--320x240.jpg)
To add to the mix there are back plunger indicators too! The measuring stem is attached to the back side of the dial housing instead of coming out of the bottom of the dial housing. It is a very popular item with lathe users.
![[Image: 480.2452.jpg]](http://littlemachineshop.com/products/Images/480/480.2452.jpg)
Clear as mud, right?
The larger gauge on the right is what most people think of as a DI. Just plain old "Dial Indicator". Very common and import versions can be purchased very cheaply. High quality name brand versions that are built to a higher standard can be quite costly as well. "You get what you pay for" as they say.
To add to Tom's point about measuring inside of holes or slots with a DTI, I will add that you can purchase accessory attachments for a standard dial indicator (DI) that will allow you to perform the same task. Just not quite as accurately as using a DTI.
To add to the mix there are back plunger indicators too! The measuring stem is attached to the back side of the dial housing instead of coming out of the bottom of the dial housing. It is a very popular item with lathe users.
Clear as mud, right?
Willie