This work is focused on the issue of non-measured points – one of the most important problems in surface texture measurements using optical methods. The fundamental aim of this research is to analyse errors of surface texture measurements caused by the presence of non-measured points. This study is divided into two parts. In the first part, circles with non-measured points were artificially created on peak portions of measured surfaces. In the second part – the results of measurement by a Talysurf CCI Lite interferometer were analysed. A measurement area of 3.3 × 3.3 mm contained 1024 × 1024 points. The measurements were performed with different intensity of light. Changes of parameters regarding the analysed errors depended on a surface type. The following parameters are susceptible to errors: skewness Ssk, areal material ratio Smr, as well as the following feature parameters: Spd, Sda, Sdv, Sha and Shv. Inaccuracies of measurement in valley parts of two-process textures led usually to larger errors of parameter computations compared with deviations in peak portions.
Worldwide Interoperability for Microwave Access (WiMAX), based on the IEEE 802.16 standards, is a technology that offers low cost mobile broadband access to multimedia and internet applications for operators and end-users. Similarly to cellular phone or other Radio Frequency devices, WiMAX has to be considered as a possible source of electromagnetic pollution and so monitoring its emission could be necessary to verify compliance with the applicable emission limits. Generally, the monitoring of the electromagnetic pollution is performed by means of a suitable measurement chain constituted by an antenna connected to a traditional spectrum analyzer. The use of this kind of device to measure the power of digital modulated noise-like signals, such as WiMAX, requires to use proper measurement methods and to carefully set many instrument parameters to obtain reliable measurement results, otherwise a significant underestimate or overestimate of the human exposure can be obtained.
In this framework, this paper investigates the feasibility of using the traditional spectrum analyzer to perform the electromagnetic pollution measurements due to WiMAX devices. A large experimental campaign is carried out to identify the most proper measurement method and spectrum analyzer settings able to warrant reliable measurements.