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Ocean Optics SAD500 Communications and Control User Manual

Page 17

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17

Technical Note 2: Correlated Double Sampling

The S1024DW and S1024DWX can be configured to utilize a data sampling technique called correlated
double sampling (CDS). In this mode, each data point consists of a sampled pixel value and a sampled
background value. The resulting spectral intensity is the difference between the pixel intensity and the
background intensity. The figure below shows the raw output of an S1024DW.

When using the S1024DW with the SAD500, the microcontroller in the SAD500 rearranges these values so
that the pixel values are transmitted first, and then the corresponding dark values.

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Pixel Number

Counts

Background Values

Pixel Intensities