The Fluid Laboratory Shock tube facillity consist of a 2m high pressure driver, a 4m low pressure driven section , and operable in a incident-shock mode or reflected-shock mode adopted a double-diaphragm method in order to make a precise operating pressure. The driver and driven section are separated by sheet metal diaphragms made of copper or steel. This diaphragm. is ruptured by a NC Milling. This shock tube could use air or helium as a driven gas. Upon rupture, pressure differential between the driver and driven creates a shock wav

e driven section and a expansion fan in the driver section. The shock wave travels through the driven section increasing temperature and pressure of the gas it passes. The spreading characteristics of the jet will be capture via schliern technique at the dump tank. Operating with the value of a1/a4=2.9, the shock tube could produce the maximum incident shock Mach number of 4 . When operating the shock tunnel at the incident shock Mach number with a 20mm throat diameter nozzle, the value of pressure and temperature of the test gas behined the reflected shock could reach 90 bar and 2300K,respectively. In order to operate the shock tunnel in a tailored condition the driver gas should be helium rather than air because, in the case of air, the emperature of air must increase very high. The theoretical test time was about 400usec in a shock tube mode and about 3msec in a shock tunnel mode with a 20mm throat diameter nozzle at incident shock Mach number of 4.