Gas sensor parts complications help: Demo board/ evaluation board and test board (for Arduino)

There are these 2 parts that are used in conjunction with the readings incoming from an acoustic, transducer gas sensing element: a demo board/ evaluation board along with a test board designated for Arduino connection. I am having difficulties with understanding what each part does and what’s the purpose that they serve. Help!

And what info have you supplied to get help about? So add information about the stuff your asking about!

I have photos right now

Show photos and possibly give part number and source if you got it from some sensor and we'll do our best

Right away

It's been a day