The Siemens SITRANS P500 transmitter SIL 2 certified by Risknowlogy. The certification is addressed the IEC 61508 and IEC 61511 standards. The certification was based on the Proven In Use route in IEC 61508. Siemens had access to over 4 million operating hours worth of data, including feedback from the end-user. This made it possible for Risknowlogy to analyse the data and to apply Proven in Use.