UL101 used to find leaks in transformers
"I have checked our transformers that are still energized over the past several years, and we have no way to look for leaks until now. The UL101 is utilized to find leaks in the transformers quickly and accurately. The repairs can often be completed without the need to de-energize the transformer, saving time and money. In one instance, we budgeted to replace all gaskets. But the UL101 showed the exact location of a leak, which required only one gasket replacement.
With a lot more transformers that we gas several times a year, we should improve on these units maintaining the proper pressures. This equipment is the only test known that will work on finding leaks in transformer tanks."