Accelerated Aging - ISO 188
This test method covers the effects of elevated temperatures on the properties of a material. Testing is performed in air for a specified period at a specified temperature. Properties are measured prior to and after high temperature exposure. Values represent a percentage change in properties with the exception of the Change in Durometer Hardness and Change in IRHD Hardness. Change in hardness values are reported as the change in hardness points.
The formula used for calculating the change in a property (except for hardness) is:
P=((A-O)/O)*100
where:
P is the percentage change in the property,
O is the original value, and
A is the value after aging.
The formula used for calculating the change in hardness is:
C=A-O
where:
C is the change in hardness,
O is the original value, and
A is the value after aging.
Three methods for testing may be employed and are listed below.
| Method | Description |
|---|---|
| A | Testing is performed in an air oven using a cell-type oven or cabinet oven with low air speed and a ventilation of 3 to 10 changes per hour. |
| B | Testing is performed using a cabinet oven with forced air circulation by means of a fan and a ventilation of 3 to 10 changes per hour. |
| C | Testing is performed using an oxygen pressure of 2.1 MPa and a temperature of 70°C. |