A reader in an esoteric field asks about the spaces on either side of the slash in the phrase "laser desorption / time of flight instrument." The phrase, he explains, describes a piece of equipment. Asks the reader, "How do you indicate that the two ideas that go together are laser desorption and time of flight instead of desorption and time?"

Dear reader: DON'T add spaces around the slash. It's not a familiar convention, and as you point out, the spacing doesn't demystify matters. You could clarify what goes with what by hyphenating the compound adjectives:

"laser-desorption/time-of-flight instrument"

An alternative solution, and one we prefer, is to recast the sentence. Here are a couple of probably nonsensical but syntactically accessible rephrasings:

"The instrument performs laser desorption and records time of flight."

"You can use the instrument for desorbing laser beams and measuring time of flight."