A fixing device includes: a heating unit; a rotatable body; an urging mechanism; first and second bearings; a frame; first and second positioning members. The ORC devices have an expected life span and the system can track the remaining life for each of the ORC devices and prompts the operator when they should be replaced. The assay device achieves greater sensitivity than conventional rapid test assays, leading to stronger andor more stable visual signals than those produced by conventional devices, easier interpretation of results, and reduced occurrence of indeterminate results. A determination is then made regarding air turbulence by determining a rate of change of signal phase among selected sets of signals received at the receiving systems. Applying the compound to an electroluminescent device provides a highly efficient blue and green emitting organic EL device.