What is the MARSSIM method? Posted on April 16, 2018July 3, 2019 “MARSSIM” is the “Multi-Agency Radiological Survey and Site Investigation Manual,” a document widely used in designing and carrying out radiological surveys in support of license termination. With the MARSSIM Method the confidence level is locked in at 95% and 3 is used for the “k²” value. This affects, then, only calculations for Ld, MDA, and LLD. This method was proposed by Dr. Alan Brodsky and was adopted in the MARSSIM manual. In truth, whether the MARSSIM method or the “traditional” method (proposed by Lloyd Currie) is used, very little difference is seen in the end result. The MARSSIM/Brodsky method should be more accurate when low background count rates are present. To match the MARSSIM methodology and Brodsky recommendations exactly, the sample counting time and background counting time should be identical, although MARSSIM does state that other methods exist that adjust for these differences. What types of radiation do your instruments detect? Our instruments detect ionizing radiation. Types of ionizing radiation are Alpha (a), Beta(ß), Gamma(y), X-ray (x). Examples of NON-ionizing radiation are microwaves and radio waves.