First of all, downtime has to be planned and coordinated. Before humans can approach the equipment, it must be disconnected and earthed. Breakers filled with SF6 have to be degassed (and because SF6 is a potent greenhouse gas, it should not be released into the atmosphere but collected and recycled).
With radiographic inspection, we can see inside equipment without having to disassemble it. But the subsequent steps and overall downtime are replaced by the far simpler and much less invasive setting up of radiography equipment. Time savings achieved means downtime is reduced from days to hours.Disassembly for inspection is time consuming and costly, and not always effective.
In below pic you can see the size and profile nozzle inside the high voltage gas circuit breaker using the radiographic way.
The pic on the left shows the nozzle shape and distance in its normal range.
The pic on the right represents the unauthorized shape than manufacture specification.
