The compact portable TR-100™ roughness tester has been especially designed for speedy and precise measurement on the shop floor. It employs a piezoelectric microsensor technique which is identical to that of high-precision laboratory roughness testers. The outstanding features of the TR-100™ include user-friendly operation and a high repeating accuracy. Simply press a button and within seconds, a microsensor in the form of a diamond stylus scans the surface. Depending on the pre-set cut-off length, the digital display shows either the roughness parameter Rz or Ra (see also DIN 4762, 4768, 4775, ISO 4288.) The latest state of the art portable surface roughness tester TR-110™ operates similar to the TR-100. However, in order to determine both parameters (Ra and Rz) it is only necessary to scan the surface once. An integrated sleeve can be slid over the sensor tip in order to protect the TR-110™ during periods of non-use. In addition to this, an automatic 1.5 minute switch-off function protects the lithium-ion battery against unnecessary discharge. The roughness parameters Ra and Rz Ra = arithmetical mean roughness value Ra, signifying the roughness parameter, is a value that is recognised and used internationally. It denotes the arithmetical mean value of the absolute values of the profile deviations within the sample area. The numerical value of Ra is always smaller than the Rz reading derived from the same sample. Rz = mean roughness depth (peak to valley) Rz denotes the mean roughness depth, i.e. the arithmetical mean of the highest single measurements of several single adjacent tracing sections.