During February of 2018, the FCC published a bulletin informing that the Commission has historically treated RF devices that transmit radio signals for purposes such as measuring the level of a fluid in a container or for measuring some quantifiable property of a material as Part 15 devices. However, due to the modulated transmission of information, the Commission determined that Part 15: intentional transmitters, were best treated as low-powered transmission communication devices as opposed to Part 18, equipment that RF energy is generated for the primary purpose of performing work energy, such as in an industrial heater or microwave oven. With additional applications, the applicability of Part 15 or 18 rules requires a case-by-case analysis.
The Commission will continue to review devices using similar techniques or frequency bands on a case-by-case basis to determine if it is appropriate to authorize them under Part 18 rules or some other rules, if applicable.