SC2/WSB2 Oxygen sensing module with SIL2 conformity

Priority on safety and reliable process monitoring in AM applications

A Safety Integration Level (SIL) between 1 and 4 (discrete) is a measure of a safety system performance. The higher the number, the lower the probability of failure on demand and the safer the system so-to-speak. Typically systems in the additive manufacturing application field require SIL1 or SIL2 certification on system level. Individual products, such as sensors, and components can be designed to meet the requirements of a system and for instance stated values of MTTF, MTBF or PFD for oxygen sensor modules can be used directly in the risk calculation for the system.

Pewatron has designed an oxygen sensor module with a SIL2 conformity level, which can be used in additive manufacturing applications. The sensor head is a stainless casing with an intelligent oxygen sensor integrated into casing.  The SC2-E1195 0…25 %Vol O2 oxygen sensor head can easily be adapted (screw-mounted) into the application without too much concern about the interface materials for tightening and can easily be replaced after EOL has been reached. The standard SC2-E1195 sensor head has an expected lifetime of 3 years, and by choice of sensor the lifetime can be extended to 5 or 7 years.

The WSB2 electronics module has features that are mandatory for the SIL2 conformity statement. The WSB2 electronics module has for instance more independent digital output terminals and an analog 4-20 mA output, thereby enabling connection to different safe and process levels. Two configurable alarm levels are also implemented into the WSB2 electronics module and the state of the gas sensor is checked and monitored from the WSB2 electronic module.