Apparatus for determining fatigue strength of polymer materials in vacuum at low and elevated temperatures

The working chamber is evacuated by ro ta ry and diffusion pumps (1 and 2, respec t ive ly) linked by connecting tubes 3, 4, and 8. To prevent oil vapors f rom the diffusion pump getting to the working chamber and to inc rease the degree of vacuum, wate r and liquid ni trogen traps (6 and 7, respect ive ly) a re included in the vacuum sys tem. Rough vacuum is produced by the ro ta ry pump which pumps out a i r f rom the working chamber through tube 8 with the vacuum valve 5 open. When the p r e s s u r e has been reduced to 1 9 10-1-1 9 10 -3 mm Hg, valve 5 is shut and valve 9 opened. The degree of vacuum is measu red with an ionization gage 42.