I used to contract for Emerson Electric (Fisher-Rosemount) and flew periodically to Germany and the Netherlands.
As device-integration specialists (getting pressure, temperature, valve, flow, etc. transmitters to talk to our process management software), we would often carry demo (demonstration, not explosive!) devices with us on the plane, both in luggage, and in carry-on.
We were never questioned. Granted, this was prior to 9/11, but...
I would often approach the security area thinking, “OK, is this the day I get thrown in jail until some bright TSA guy figures out what the heck this pipe-bomb looking thing with the extruding wires actually is?”
Ha! I know what you mean. Twenty years ago, I worked for an engine company, and carried a whole toolbox full of stuff on the plane to test customer applications.
In the toolbox on one occasion, I had a 1 1/2” diameter pipe (an exhaust pipe extender) and an electronics box complete with circuit board, digital readout, and thermocouple wires, etc.
As my toolbox went through the x-ray, one attendant looked at another, and said (I kid you not), “I didn’t see anything. Did YOU see anything?”