A new application of laser displacement sensors in measuring surface texture has been reported from industry recently. To achieve high measurement precision, laser sensors with high-resolution, which are expensive and usually means high-laser-class, are required, because if low-resolution sensors are used, the surface signal could be hidden in the internal noise of the sensor. In this paper, the mean of a number (N) of measurements of a specific distance between the sensor and the measured point is used to better represent the distance and reduce the internal noise. An artificial neural network has been trained to estimate a suitable value of the number N for a predetermined measurement precision. This way the measurement precision can be dramatically improved whilst maintaining a suitable dynamic response. The method is then further developed for continuous surface profile measurement for in-process purposes. Studies on filtering different components of surface texture using Gaussian and triangle filters have been carried out. The filtering results can be used to evaluate surface finish parameters, such as roughness and waviness.

In the paper some ways of straightness and roundness measurements with multipoint methods are presented. They are based on workpiece surface measurement in limited number of regularly dislocated points and on reconstruction of an actual profile. For this purpose different interpolation methods can be applied: linear function, polynomial, trigonometric series, third order spline interpolation. The main point when using these methods is to choose a number of measuring points correctly. It depends on character of examined surface, applied interpolation method and acceptable measuring error. These methods can be used for coordination machines with touch trigger probe. Comparison tests were performed using a device for straightness and roundness referenceless measurements.

Methods and devices for on-line measurements of produced thin metal tubes and rods are proposed. They are based on the use of a monitored article as a conductor of synthesised TEM-transmission line section. Resonance frequency of electromagnetic oscillations of such line section and period of pulses sequence excited in it serve as informative parameters of the designed length sensors.

The paper deals with the active error compensation effected by using links or components, made from piezoactive (piezoelectric or magnetostrictive) materials. It is shown that by implanting of active links into the technological chain of the measuring equipment both static and dynamic errors can be sufficiently reduced. Some considerations according to new approach to error compensation circuits and actuators are presented. Compensation covers not only generally accepted measurement systems, but also opens new ways of increasing the accuracy of such typical components of technological machines as beddings, slideways, fixing and datum keeping surfaces. Two- and three-dimensional correction methods and means are presented.

Temperature behaviour of machine tools is one of the main reasons for process dispersion of the modem accurate production. This paper presents a comparison of the effect of thermal expansion and positioning measuring System on the production accuracy of machine tools. In the project the positioning accuracy of pulse encoders and linear positioning measurement systems (two types) in different thermal conditions was compared and analysed. Both measuring systems were used interchangeably on each machine tool at the same time.
The test environment includes a modern sheet metal turret punch press and two horizontal machine centres, one in laboratory and one in industrial environment. The initial state of the machinery was examined in a throughout inspection using both conventional measuring equipment and a modern quick test method (doubie ball bar). All workpiece and test piece measurements were performed using a co-ordinate measuring machine in an accredited calibration laboratory.