Every occupation has its own jargon. Use enough in character dialog to sound authentic, but don’t boggle the reader’s mind with too much technical terminology or acronyms, which should always be defined the first time they’re used. If several pages or chapters separate their next use, remind the reader. This can be easily done via dialog. For example:
“The ARU went out again,” John said.
“That’s the second time this month the auxiliary refrigeration unit has gone on the fritz,” Bill grumbled in reply.