A method of auditing cartridges and empty cells in a storage library system including a plurality cells for storing cartridges and further including a robotically actuated picker assembly, the method comprising: providing a radio frequency sensor on the picker assembly; positioning a cartridge having at least one radio emitting chip within the cells so that the presence of the radio emitting chip can be detected without unloading the cartridge from the cells and operating the picker in a manner to search for the presence of the radio emitting chip within each cell for auditing numbers of cartridges and empty cells in the storage library system by moving the picker with the radio frequency sensor from one cell to the next to measure the presence of the radio emitting chip for each cell.