Canon XRD9827REF - Manual (Page 16)

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PRELIMINARY
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Figure 13. Gray-scale Target Scan
22. To demonstrate the noise component is contributed from the CIS, we hooked up a DC reference to the
scanner and the results are shown below in Table 1.
REFERENCE DC (V) STANDARD DEVIATION SYSTEM SNR (dB) W/O CIS
NOISE COMPONENT
2.0 2.144328 62.6117
2.5 3.48261 58.3988
3.0 2.399188 61.6356
3.5 1.983461 63.28842
Table 1. Signal-to-Noise Ratio of the XRD9827REF with DC Source as Input (No CIS Noise
Component)
As we can see from Table 1, the SNR falls into the range of 58 dB to 63 dB when a DC reference is used
as input to the XRD9827REF. The system alone gives a 9 1/2 to 10 bit performance. The largest noise
source we saw in previous scans came from the CIS. A typical plot of the DC reference is shown in Figure
14.