A technique that is usable with a fuel cell stack includes providing a fuel flow to the stack, changing the fuel flow and observing a response of at least one cell voltage of the stack to the change in the fuel flow. The damper unit includes a frame defining an air flow opening, a damper vane for opening and closing the air flow opening, and a stepper motor for turning the damper vane between the open and closed positions. A corresponding reference voltage is generated after the bit line is isolated. At least one of the processing units sends the identification label to a remote station. 5% to 15% by weight of a trimethylolpropane co-solvent; and from 0. The device comprises a look-up table for providing a first variable m and a second variable J satisfying the equation N=2m\xd7J; and an address generator for generating a read address depending on the first and second variables m and J provided from the look-up table.