A method and apparatus for compressing signal samples uses block floating point representations where the number of bits per mantissa is determined by the maximum magnitude sample in the group. When the level two controller detects that a line is valid and dirty in level one, the level two memory need not update its copy of the data. The luminaire managers include transmitters for transmitting status information about their respective luminaires and third-party devices to a network server. To prevent damage incurred during a bonding process, the aforementioned metal layer may define a frame with an outer periphery and an inner periphery. The assist gas is nitrogen or a nitrogenoxygen mixture. The personal conveyance may also include a lowered centre of gravity which contributes to further improved stability and again lessens the likelihood for injury to the ankles of users.