Presentation is loading. Please wait.

Presentation is loading. Please wait.

MEASUREMENT OF SURFACE FINISH 1.SURFACE TEXTURE: The characteristics quality of an actual surface due to small departures from its general geometrical.

Similar presentations


Presentation on theme: "MEASUREMENT OF SURFACE FINISH 1.SURFACE TEXTURE: The characteristics quality of an actual surface due to small departures from its general geometrical."— Presentation transcript:

1 MEASUREMENT OF SURFACE FINISH 1.SURFACE TEXTURE: The characteristics quality of an actual surface due to small departures from its general geometrical form which, occurring at regular or irregular intervals, tend to form a pattern or texture on the surface 24/03/20121Lec # 27 & 28

2 1.SURFACE TEXTURE – The General form relates to the dominant shape of surface which it is intended to reproduce, & constitute a first approximation to the design form – It is possible for two or more kind of irregularity to be combined in the complete texture of a surface in such a way that they are not readily distinguishable individually by eye or touch – Surface texture varies according to the machining processes used in producing it (eg. Metal machining) 24/03/20122Lec # 27 & 28

3 1.SURFACE TEXTURE – Difference in surface texture are apparent by visual examination & can be felt readily by passing a finger nail over the surface – The texture of surfaces can be regular or non- regular in character – FACTORS PRODUCING SURFACE IRREGULARITY: Faulty tools Inherent imperfections in the m/c tools Errors due to personal element 24/03/20123Lec # 27 & 28

4 2. METHODS OF MEASURING S. FINISH 1.SURFACE INSPECTION BY COMPARISON MEHODS: these include: i.Touch inspection ii.Visual inspection iii.Scratch inspection iv.Microscopic inspectioon v.Surface photographs vi.Micro interferromter vii.Wallace surface dynamometer viii.Reflected light intensity ix.Comparison by standard specimens 24/03/20124Lec # 27 & 28

5 2. METHODS OF MEASURING S. FINISH 2.Direct Instrument Measurement i.Intersection method ii.Interference method iii.Stylus method 24/03/20125Lec # 27 & 28

6 3. NUMERICAL EVALUATION OF SURFACE TEXTURE Practice adopted for obtaining numerical evaluation of surface texture is to use a parameter based on the cross-sectional profile of the surface under examination There are two system for Numerical evaluation of surface finish, i.e: a.Centre line average (CLA) b.Root mean square (RMS) value of height undulations of the surface The CLA system is more popular in UK, while the RMS is more popular in USA 24/03/20126Lec # 27 & 28

7 3. NUMERICAL EVALUATION OF SURFACE TEXTURE FOR EQUATIONS of CLA & RMS, AS DEOMOSNTRATED ON BOARD 24/03/20127Lec # 27 & 28

8 4.TOMLINSON SURFACE FINISH RECORDER As Demonstrated for figure on next slide on board 24/03/20128Lec # 27 & 28

9 4.TOMLINSON SURFACE FINISH RECORDER 24/03/20129Lec # 27 & 28

10 5.ADVERSE EFFECTS OF POOR SURFACE FINISH Book: Engineering metrology & instrumentation Page#: 234 DO YOUR SELF 24/03/2012Lec # 27 & 2810


Download ppt "MEASUREMENT OF SURFACE FINISH 1.SURFACE TEXTURE: The characteristics quality of an actual surface due to small departures from its general geometrical."

Similar presentations


Ads by Google