In the fast developing technology of pellistor manufacture@ manufacturers have used many different methods of showing how their pellistor withstands the effects of poisoning by the many contaminants met with in industry today. Users have difficulty in making comparisons between the claims made by the different manufacturers for their products. The members of the EEMUA Instrument Committee decided that a standard test method to make such comparison was needed and this document is the result of that decision. It is hoped that the use of this method will assist users in deciding which pellistor best meets their requirements at the most reasonable cost while establishing a standard method of making comparisons.