0016// Surface Flatness Measurement

Flatness is one of the important form control commonly use in different industries. Flatness control can use on sealing surface for vacuum design; it also can use on mating surface for assembly with demanding alignment requirement.

However, meausurement for flatness can be tricky and people usually will mix up with parallelism measurement. (which discussed in http://gbwonggbwong.wix.com/gb-graphic-design#!0015-Parallelism-Measurement/c2211/5647eb4a0cf2708e001b1dc2)

Therefore, today we will discuss about how to use dial indicator to measure flatness without using coordinate measurement machine (CMM).

Defination of Flatness:

Y14.5-2009 , 5.4.2 Flatness is the condition of a surface or derived median plane having all elements in one plane. A flatness tolerance specifies a tolerance zone defined by two parallel planes within which the surface or derived median plane must lie.

So, flatness control can be on surface or derived median plane. In this post, we will focus about surface flatness.

Equipments needed to measure surface flatness:

1. Granite table

2. Dial Indicator with bend probe

3. Screw Jack x 3

Set-up and Measurement