The heated shock tube (HST) was built in 1990 and used in the past for performing studies on ignition delay time measurements and soot extinction measurements. Its driven section has an internal diameter of 52 mm, a length of 5.15 m and a high-pressure 2 m long driver section (114.3 mm i.d.). Double diaphragm technique is used to generate the shock waves (terphane diaphragms). With this configuration observation times up to 4 ms could be obtained behind reflected shock waves, with maximum pressures of 40 bar. As part of the FUN-PM project, a new end-section was designed and constructed to allow coupling with the optical fibers for extinction and Rayleigh scattering measurements. Work is ongoing for completing the set-up and testing of the new measurement system.