An oven for temperature cycle testing at high and low temperatures. The need to measure stress relaxation at high temperatures and stress relaxation due to material shrinkage at low temperatures is being discussed at the ISO TC45 committee. Temperature cycle testing can provide important information, such as the factors causing leaks due to seal shrinkage. In the automotive industry, in particular, leakage caused by seal shrinkage has become a major problem, and temperature cycle testing provides crucial information regarding this.