An air management system that allows safe and convenient forms of interval training exercise to be performed on pneumatically elevating rebound exercise equipment. The user identifies target servers or a network representing several targets to scan, and the system scans the specified servers to identify which support voice over IP services. The taper waist portion may be formed into a loop with a small bend radius without loss, and sensors embodying the claimed invention are particularly suitable for in-vivo measurement of pressure, the taper waist portions advantageously being arranged in contact with a membrane which deflects according to surrounding pressure. First angle values through the first angle measurement mechanism and second angle values through the second angle measurement mechanism are then provided simultaneously; and from these first angle values corrected on the basis of a comparison of the first and second angle values are deduced.