An official website of the United States government.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Radiation Protection

What is the relative shift?

The relative shift expresses the width of the grey region, or shift, image of shift, in terms of the number of standard deviations of the measurement data, number of standard deviations image, and is designated as (DCGLW - LBGR/number of standard deviations image) or equation image. The degree of difficulty in distinguishing the LBGR from the DCGLW depends on the variability of the data as well as the size of the shift. The smaller the relative shift, the larger the number of samples. The number of samples increases rapidly with only small decreases in the value of the relative shift when the value of the relative shift is below one.

For more information on the MARSSIM process, visit Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM).

Return to Frequent Questions about Radiation Regulations, Guidance and Compliance.