A MANUAL STRESS CRACK TESTER IS A DEVICE TO TEST A PLASTIC BOTTLES ABILITY TO WITHSTAND INTERNAL PRESSURE. TYPICALLY A BOTTLE IS FILLED WITH WATER UP TO THE FILL POINT, AN ADAPTOR IS PLACED INSTEAD OF THE USUAL CAP, IT IS PLACED IN THE MACHINE AND 5 BAR AIR PRESSURE APPLIED, THE BASE OF THE BOTTLE SITS IN A CAUSTIC SOLUTION TO ACCELERATE DEGREDATION OF THE BOTTLE. TIME FOR BOTTLE TO BURST IS MONITORED AND RECORDED. THE VALVES ARE OPENED MANUALLY, BOTTLE FAILURE AND TIME MONITORED BY OBSERVATION.

GIR'S 1 AND 6. TEXT TO HEADING 9024.