Frequently Asked Question
Could you please confirm the following with regards to verifying the SIL for a Temperature Trip. Can the sensing element (such as the Thermocouple, RTD etc.) be considered as a "passive" from a SIF loop and be ignored from the PFDavg. calculations. This w
Last Updated 5 years ago
In your SIL verification you will need to consider all components that are necessary to detect the hazard and bring the process to a safe state. How does the temperature transmitter measure temperature without the RTD, TC? If you want to model a scenario where you are ignoring the sensing element, you will (in the current version of the software), define a "user defined" component as the sensing element and specify if this is a TC or RTD (the failure rates of the transmitter will depend on the TC/RTD selection). You could set the failure rates of the sensing element equivalent to the failure rates of a wire, i.e. 1E-9 for SU and 1e-11 for DU.