Short for oxidative induction time. A small sample is heated in a differential scanning calorimeter under oxygen, and the time before it starts to oxidize shows how much stabilizer is left. Standard OIT runs at 200 degrees C and atmospheric pressure, while high-pressure OIT runs cooler under pressurized oxygen and detects more stabilizer types. HDPE geomembrane specs commonly ask for at least 100 minutes standard or 400 minutes high-pressure OIT.
OIT came back at 140 minutes on the conformance sample, comfortably over the 100 in the spec.
Also heard as
- oxidative induction time
- Std-OIT
- HP-OIT
Related terms
HDPE
High-density polyethylene: the stiff, chemically resistant polymer used for most landfill and mining geomembranes.
Carbon black
Fine black pigment blended into polyethylene geosynthetics, usually at 2 to 3 percent, to block ultraviolet damage.
Stress cracking
Brittle cracking of polyethylene geomembranes under long-term tension well below their yield strength.
UV resistance
How much strength a geosynthetic keeps after exposure to ultraviolet light in an accelerated weathering test.