A sample 10 is measured by generating ultrasound at 12, for example by using a laser 22 and spatial light modulator 26. Thus, the semiconductor memory device includes a plurality of memory cells which store n-bit data for one cell. A field plate layer is formed on the first dielectric layer juxtaposed on at least the total surface of the emitter region and adjoining portions of the surface of the base region. In the multi-electrode crisscross array of the present invention, the geometrical placement of the electrodes increases the efficiency of the system via two parameters, the close proximity of oppositely charged electrodes and the multiplicity of electrodes configuration, that is, crisscross arrays of electrodes. A memory of the device includes code executable by the device and configured to adjust the baseline sensitivity setting based upon the sensed operating condition. The method includes a mapping mechanism wherein when a map entry for a block being written to for the first time during a session exists, then another map entry is created and all later sessions are applied to it.