Starrett SR200 Surface Roughness Tester - Manual (Page 21)

SR200 Specifications subject to change 5.1
Chapter 5
Making Measurements - Technical Considerations
Operating Notes
Before measurements are made, there are a few general points of procedure which should be
observed.
1. The surface to be measured must be free from vibration and the instrument must be
completely steady during a measurement.
2. Always turn the pick-up so that the stylus is visibly perpendicular to the surface to be
measured.
3. Set the display-traverse unit so that the traverse is made parallel to the surface being
measured.
4. After a measurement, the traverse unit can be removed from the surface as soon as the
pick-up completes its return stroke. The display will remain visible.
5. Where the texture of a surface has a predominant direc tional character (LAY), it is usual to
traverse across the lay, not along it.
On a horizontal surface
1. Use the biased pick-up holder on the display-traverse unit
2. Clean the surface to be measured, so that it is free from abrasive material, grease, suds etc.
This is necessary to ensure accurate readings and to reduce wear on the skid.
3. Make the cut-off/length and parameter selections required
4. Position the display-traverse unit and pick-up so that the stylus contacts the surface and
the pick-up is approximately parallel to the surface. Make sure that the length of surface is
sufficient for measurement, remembering that the traverse motion is inwards towards the
display-traverse unit.
5. Press the Measure key. When the traverse is completed, the results are displayed and the
pick-up returns to its extreme outward position.
6. If an error message is displayed, identify the cause, correct it and repeat the measurement.
On other surfaces
On a vertical surface:If necessary, hold the display-traverse unit by hand on the surface,
making sure that it does not move during the measurement.
In a small deep bore: Fit the optional extension rod between pickup and holder.