See the press release: Halogen amperometric total residual oxidants sensor is accepted by IMO’s GESAMP subcommittee as equivalent to the traditional DPD test. In the article, Halogen Systems president Michael Silveri is quoted as saying, “This makes the change from a DPD instrument to Halogen’s amperometric sensor straightforward. While case-by-case is required by the approval authority, repeating the initial type-approval testing is not required. With our new side stream system,