Previously available analog domain decimation techniques are limited to simple equally-weighted averaging of photosite outputs. The solutions is also targeted to an apparatus and a computer-readable storage means. The transflectance probe comprises a tapered tubular housing having an inner reflective surface, an optical rod having an outer reflective surface, and a detection window which serves as an interface between the probe and the surface of the sample matrix. A diode coupled between the secondary winding of the transformer and the flash capacitor provides the output voltage according to the secondary voltage.