Design of Functional Safety Pressure Transmitter and Safety Assessment

Based on functional safety standard IEC61508, this paper studies the functional safety approaches of the pressure transmitter. Following the 1oo1D architecture, self-diagnostics measures are used in this functional safety pressure transmitter. In order to improve diagnostic coverage, dual CPUs are used to compare results at different calculation stages. The FTA analysis and Markov model are used for safety verification. Furthermore, the safety failure fraction (SFF) and probability of failure on demand (PFD) are analysed, and the results indicate that safety integrity level is SIL2.