An apparatus for detecting flashback occurrences in a premixed combustor system having at least one fuel nozzle includes at least one photodetector and at least one fiber optic element coupled between the at least one photodetector and a test region of the combustor system wherein a respective flame of the fuel nozzle is not present under normal operating conditions. While the transaction manager is paused, the transactions that the transaction manager is executing may not be allowed to complete. The service priority coverage area and emergency service personnel assigned the service priority are defined on a dynamic basis by the centralized emergency services agency and are indicated by a priority call access code that is transmitted to the emergency service personnel. The workpiece includes a peripheral surface with a cross-section extending along the workpiece axis and defining an arc substantially identical to the arc of the root surface of the hourglass worm.