article heading should be "Experiment setup" or "Experimental setup"?

My advisor insists on using a heading "Experimental Setup" in his science journal articles. I always cringed a little, thinking it should be "Experiment setup" instead. Now I am writing an article and in his edits he wants me to add the -al.

To me, "experimental setup" sounds like the setup itself is experimental, but "experiment setup" sounds more like we set up an experiment. Technically, we set up an experiment, and the setup itself was not the experiment. I suppose the root of my question in this case is, is the word "experiment" supposed to be an adjective or a noun? Hopefully that explanation makes my grievance clear..

English is his 2nd language, and my first, so he won't mind me questioning it.

Does anyone have a definitive answer to that one? Thank in advance! -Curious Grad Student

He is following convention. Try looking at other papers, this is the standard term.

If you say "Experiment Setup" you may feel better but your readers will wonder what you are trying to prove - worse they may think you have made an error.

Maybe, as a compromise, you could say "Setup of the Experiment" (?)

Here's chapter subheading C from the book Quantum Mechanics by K. T. Hecht:

C   Complementary Experimental Setup

The Ngram Viewer sides with your advisor, finding the usage with -al over fifty times as popular as the usage without.

I understand your unease. It's the same one I get when I hear the words "oversight committee." Are they overseeing something or overlooking it?