EEMUA Publication 242

The first edition of EEMUA Publication 242 outlines good practice in carrying out proof testing of Instrumented protective systems (IPS) and writing proof testing procedures. EEMUA 242 provides an overview of the high level requirements for proof testing, including the intent behind the tests. Detailed guidance covers the testing of particular instrument types and how to document a proof test in a standard proof test routine template. This publication is intended for site engineers working with system designers on new IPS, but is also helpful for legacy IPS where documentation of the design is incomplete.

The emphasis is on the practical aspects of proof testing, given that every process plant has its own specific requirements and that the ideal of out of service end-to-end testing may rarely be achievable because of operating constraints. EEMUA 242 covers an area which is outside the scope of most standards, and for many users would be a very steep learning curve without guidance. It is based on the experiences of testing real process plant equipment and has been extensively reviewed by industry practitioners.

Applying EEMUA 242 may assist in fulfilling some of the requirements of Clause 16 of IEC 61511-1 which places specific requirements on Safety instrumented functions (SIFs), which are IPS protecting safety hazards with a required integrity of SIL (Safety integrity level) 1 or above. This guidance should be applied to IPS which are SIFs, but may also be applied to other IPS, including those protecting non-safety hazards or those with below SIL1 integrity. Overall requirements for proof testing of IPS and how this is related to the safety lifecycle is established in other documents such as IEC 61511.