metrology 3 sem

Most commonly used roughness grades in tool works i

• N1 to N4
• N5 to N8
• N1 to N12
• N9 to N12
• Text for option 5 (optional)

If Ra value corresponding to roughness grade N6 is o.8, value for grade N7 Is

• 1.6
• 1
• 0.4
• 2.4

Ra value is expressed in

• meter
• mille meter
• inches
• microns

The direction of predominant surface pattern on a surface is called

• primary texture
• secondary texture
• waviness
• lay

Term ‘lay’ is used to denote

• waviness
• roughness
• direction of feed marks
• surface texture

One of the methods used in surface inspection by comparison is

• inspection by Tomlinson suface meter
• use of straight edge
• inspection by profilometer
• microscopic inspection

One of the causes for the Secondary texture is

• production process
• primary texture
• tool feed marks
• hard spot on work

Secondary texture is also known as

• roughness
• flatness error
• waviness
• straightness erro

Primary texture is also known as

• roughness
• flatness error
• waviness
• vibration

In the symbol shown, ‘d’ indicates

• bright
• darkness
• crests coincide
• none