EN ISO 7536:1996 PDF

Overview - EN ISO 7536:1996 (ISO 7536:1994)

EN ISO 7536 specifies the induction period method for determining the oxidation stability of gasoline (finished aviation and motor gasolines). The test accelerates oxidation in a sealed pressure bomb charged with oxygen (≈690 kPa) and heated near 100 °C (98–102 °C). Pressure is monitored until a defined breakpoint is reached; the elapsed time is the observed induction period. Results are reported as the induction period at 100 °C (IP100).

Keywords: oxidation stability, gasoline, induction period method, pressure bomb, ISO 7536, EN ISO 7536.

Key topics and technical requirements

• Test principle: oxidize 50 ml sample in a pressure bomb filled with dry oxygen (~690 kPa) and heat in a boiling water bath (98–102 °C); record pressure vs time until the breakpoint.
• Breakpoint definition: a point in the pressure–time curve preceded by a pressure drop of exactly 14 kPa within 15 minutes and succeeded by a drop of not less than 14 kPa in 15 minutes.
• Temperature correction: convert observed induction period IPt at test temperature T to IP100 using:
  • For T > 100 °C: IP100 = (IPt)[1 + 0.101(Ta − 100)]
  • For T