ISO 6518-2:1995

Overview - ISO 6518-2:1995 (Ignition systems test methods)

ISO 6518-2:1995 specifies electrical performance and function test methods for battery‑supplied ignition systems used on road vehicles with spark‑ignited internal combustion engines. This second edition replaces the 1982 version and introduces two standardized test approaches (Method A and Method B) to obtain the parameters needed to calculate system output energy. The standard is intended for repeatable bench testing of ignition coils, distributors, switching devices and complete ignition systems.

Key topics and technical requirements

• Two test arrangements
  • Method A (spark gaps) - measures inductive spark energy (Espi) using controlled spark gaps; output called spark energy.
  • Method B (Zener diode string) - measures Zener discharge energy (Ezd) with Zener diode strings (1 kV for single‑ended coils; 1 kV and 0.5 kV for double‑ended coils); recommended for comparative coil and current‑interruption testing.
• Components and system configurations
  • Single‑ended and double‑ended coils, ballast resistors, distributors (mechanical or distributorless), auxiliary switching devices and plug‑top coils.
• Measured parameters
  • Available voltage (Uav), minimum available voltage (Uavm), secondary output voltage (Us), spark/Zener discharge duration, maximum spark/discharge current (Ispm / Izdm), secondary voltage rise time, coil primary induced voltage (Upind), ignition‑limiting load resistance (R15kV), average current input.
  • Energy calculations: Espi and Ezd are calculated by integrating measured voltage × current over the spark/discharge duration.
• Test equipment and limits
  • Oscilloscope: ≤35 ns rise time, ≥10 MHz bandwidth; overall measurement uncertainty <3%.
  • Voltage probe input capacitance ≤5 pF where required; current probe suitable d.c. to 10 MHz.
  • Load capacitances to simulate real cable/plugs: e.g., 50–55 pF for distributor systems; 25–30 pF for some static systems.
  • Standard test conditions guidance (e.g., supply voltage 13.5 V nominal, defined ambient temperatures and rotational frequencies for drive stands).

Applications and who uses this standard

• Automotive OEMs and ignition component manufacturers for design validation, performance benchmarking and production verification of ignition coils, distributors and electronic control units.
• Independent test laboratories and certification bodies performing compliance or comparative testing of ignition systems.
• R&D and durability engineers assessing spark energy, coil stress, and the effect of fouled spark‑plugs or electrical loads on ignition performance.
• Service and calibration facilities seeking standardized bench test procedures.

Related standards

• ISO 6518 series (general title: Road vehicles - Ignition systems). See ISO 6518‑7 (Vocabulary) and ISO/TC 22, Subcommittee SC1 (Ignition equipment) for related work.

Keywords: ISO 6518-2, ignition systems, road vehicles, electrical performance, test methods, spark energy, Zener discharge, ignition coil testing, battery-supplied ignition systems.