Roughness – Machined Ra are Machined Surfaces, achieved through machining the surface.  Machined surfaces are measured with a surface roughness gauge. These consist of a stylus attached to an arm which moves over the surface to record and measure the roughness over a specified distance recording peak to valley heights. The measurement would be in Ra, Rz or similar.

In protective coating applications there is a requirement to measure surface roughness. Measurements of Surface Roughness are expressed in terms of Ra, Rz or Tp. These values include peak-to-valley profile measurement in combination with an assessment of the frequency of peaks within the sample area.

The Elcometer 147 Cambridge Weld Gauge measures many aspects of welds both in metric and imperial units and includes:

• Angle of preparation 0 to 60º
• Misalignment (high – low)
• Fillet weld throat size
• Fillet weld length
• Excess weld metal (capping size)
• Depth of undercut
• Depth of pitting
• General linear measurements up to 60mm
• 2mm edge roundness test

The Elcometer 129 Roughness Comparators allow the estimation of surface roughness, by both touch and sight. Elcometer 129 Rubert Comparators are available in two models :

The Elcometer 129 Rubert – available in grit and shot Versions
The Elcometer 129 Rugotest – includes the shot and grit profiles on the same block

Available in metric units only roughness is displayed on both classes and groups for easier identification.

The TR3110 Portable Roughness Tester (previously the TR110) is the latest instrument combining electronics and probe in an Integral Unit. It is widely used to test various metal and non-metal processing surfaces. It determines both roughness parameters Ra and Rz within a wide measuring range. The piezo-electric pich-up stylus with diamond tip assures a very reliable measurement within tolerances conform with ISO class 3. Roughness parameter Ra conforms to ISO and Rz conform to ISO and DIN