Instrumentation Engineering. Basically controls work. Heat treat processes in a aerospace manufacturing company, did some design and testing in a mechanical and metallurgical lab. Some R&D on some military equipment. Did ten years in building controls across a 30 building medical campus which did a whole range from patient care to research. My field also takes in petrochemical to resource extraction to process control. Process control from the heat treat furnaces and ovens to waste water to, well anything that can be measured and controlled. From what sensors to use, dealing with the signal, taking it and using it to control vales, fans, pumps...
I taught a little of it and a good example I used was a car. Your measuring the air temperature, the manifold pressure, fuel pressure, throttle position, engine temperature, engine speed, controlling the ignition, the fuel injectors, the transmission sensors, displaying pertinent information to the driver, data logging... Worked on automation, packaging equipment. I was real close to working at a drug manufacturing plant but I would always have to wear a lab coat and that is something that would be painful to me. Now if you are familiar with the field I just went on and on when I could have just said which one I was in.