Measurement exchange networks and protocols to exchange measurements of a parameter amongst devices (e.g., IoT devices), select the best measurement(s), accuracy/precision-wise, and determine a process variable for a control system based on the selected best measurement(s). A device may select a peer-provided best measurement to output as the process variable in place of a local measurement, and/or compute the process variable from multiple best measurements (e.g., local and/or peer-provided measurements). Metadata may be used to select a measurement(s) and/or to increase reliability/trust of exchanged data. In this way, each device of an exchange group/network may obtain the highest measurement accuracy of all available collocated sensors with little or no additional processing or cloud connectivity. A best measurement(s) may be selected based on measurement quality specifications extracted from metadata, measurement qualities computed from measurements of respective sensors, locations/proximities of the sensors, a policy(ies), and/or device IDs (e.g., extracted from metadata).