This invention uses the technologies of the Internet, website building and databases to create a referral resource system, which list individual contractors and businesses and the products and services they offer under the local church in which they are members. In one arrangement, the devices and methods make use of an expandable body that includes an internal restraint coupled to the body. Detections of the light portions acquired during the calibration interval are processed to compute at least one algorithm compensation that causes a first result related to the optical property for the first subregion to be substantially equal to a second result related to the optical property for the second subregion. Clock recovery circuitry may be employed on one side of the isolation barrier to extract timing information from the digital signal communicated across the barrier, and to filter the effects of phase noise introduced at the barrier.