This varies tremendously with the application/instrument desired. An instrument for small-scale applications (education, medical, and etching) could be easily manufactured in a small, (high quality) machine shop. The electronics are well defined and pre-manufactured detectors, flow gauges, etc. are readily available.For large-scale applications (drinking water, wastewater, etc.) no new technology is needed but optimization studies would have to be undertaken (optimum frequency, electrode gaps, etc.). Items such as gas handling pumps, detectors, diffusers, etc. are commercially available. We developed a lab scale working model that uses one or two ozone tubes that would cost a few hundred dollars each (maximum). To make a large-scale ozone generator, a large number of these tubes would be placed in parallel.