A positron emission tomography detector module includes an array of scintillation crystal elements and a plurality of photosensors arranged to at least partially cover the array of scintillation crystal elements. A unique relationship ID is assigned to relationships between any two nodes of the qualifying schema which are both associated with the same data instances. A set value for an expansion valve is adjusted by changing the amount of screwing of the pressure sensor to thereby change the load of the compression coil spring. The first switch maintains a name server database about its local node devices, as does the second switch. Each sub-detector can incorporate a detector element, such as a detector element incorporating one or more diodes, a detector element incorporating a crystal, a detector element incorporating a solid-state device, or a detector element incorporating a scintillator. The method comprises the following steps:.