Simple Apparatus in an Unclassified Area

[hvrm]

Hi all,
I'm wondering if a simple apparatus in an unclassified area can be used. I'm thinking about a simple transducer that isn't UL or CE rated on a custom circuit board for our controls.

Appreciate comments and ideas on this.
Thanks!

 

[tom baker]

A custom board is not a product that falls under the scope of the NEC, which is for premise wiring.
Your question is more appropriate for a listing agency.