Microwave sensors find a continuously increasing number of applications for in-line sensing of materials properties and industrial process control. The first part of the talk will focus on the implantation of the latest two-parameter microwave sensors for the rapid determination of material properties. Two classes of two-parameter sensors will be presented. In the second part of the talk multi-parameter sensors will be introduced. With such sensors, dielectric spectra of materials are interrogated over wide frequency ranges at distinct spot frequencies. The most advanced sensors of the latter kind working either in frequency domain or in time domain, and based on ultra-wideband (UWB) bandwidths, will be shown and special applications will be presented.