TR 10 Test
The TR10-value according to ASTM D 1329 or ISO 2921 states the value in °C at which a specimen which was stretched 25% or 50% recovers by 10 % after freezing. This value is the most informative cold temperature guide value for the assessment of sealing characteristics of O-rings or similar seals which constitutes a conservative low temperature limit. This means that based on experience even dynamically applied O-rings or O-rings which are exposed to pressure at low temperatures still seal until the TR10-value. For lower requirements, meaning static sealing against ambient pressure, O-rings can still seal until approx. 10-15 °C below the TR10-value according to experience. The TR10-value usually is determined on standard test pieces which are stamped out of test slabs. However, it can also be measured directly at O-rings with a cord thickness up to 3,53 mm and an inner diameter of at least approx. 15 mm.
From an application-specific point of view the TR10-value is the most informative cold test for O-ring applications and moreover for most other sealing applications. Therefore, it is ascertained as material property of many elastomer materials for sealing applications. This TR10-value can also be determined in the O-Ring-Test-Laboratory Richter. A further advantage of this TR-test is that the continuous defrosting behaviour of an elastomer sample is depicted meaning this test shows the temperature dependent elasticity of a rubber material below room temperature very well and helps with the comparing assessment of different materials for example by forming the temperature difference between the TR10- and the TR70-value in addition to the TR10-value, the lower this value is the faster the rubber material regains its full elasticity.