Fire detection and smoke detection use an image capturing device to obtain images from a predetermined area and adopts an RGB color model based chromatic and disorder measurement for extracting fire pixels and smoke pixels. The gas sensor signal may be measured during the first period of time to determine a first signal value and during the second period of time to determine a second value. An output signal on the node includes the first and second samples and has a bit rate that is N times the rate of the clock signal. The master site and a remote site then conduct communications therebetween by frequency-hopping andor orthogonal frequency multiplexing among the clear channels using an a priori known PN sequence. Thereafter, a flex circuit can be attached to the load beam and intermediate flexible circuit to provide electrical connections to the magnetic head through the intermediate flexible circuit.