Microwave instability in the Super Proton Synchrotron (SPS) at CERN is one of the main limitations to reach the requirements for the High Luminosity-LHC project (increased beam intensity by a factor 2). To identify the impedance source responsible of the instability. beam measurements were carried out to probe the SPS impedance. The method presented in this paper relies on measurement... https://www.chiggate.com/3m-speedglas-9002nc-welding-helmet-fashion/