What is the diagnostic coverage (DC)?
The diagnostic coverage (DC) states the effectiveness of the diagnostics that can be achieved as a ratio of the rate of dangerous failures detected to the rate of all dangerous failures. Failure Mode and Effects Analysis (FMEA) or similar methods can be used to estimate the DC in most cases. Classification by range: minimal DC < 60%, low 60% ≤ DC < 90%, medium 90% ≤ DC < 99%, high 99% ≤ DC. For estimates of DC in pneumatic systems, applicable guidelines include the following from EN ISO 13849-1, Appendix E: indirect monitoring (e.g. monitoring using pressure switches, electrical position monitoring of actuators): 90% to 99% DC, regardless of application; direct monitoring (e.g.
