Who decides the limits for set test results on the testers?

Most manual PAT testers in the market will have preset values stored in the tester which is set by the manufacturer, these typically tend to be worst case scenario values. Some manual testers will allow further tests to continue once the competent person has overruled the value displayed based on knowledge of that equipment type. Some of the more enhanced automated testers will allow the user to write their own test sequences based on the equipment types they are testing.