USB-1608FS User's Guide
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Figure 9. ADC Transfer function with gain error
For example, the USB-1608FS exhibits a typical calibrated gain error of ±0.04% on all ranges. For the ±10 V
range, this would yield 10 V × ±0.0002 = ±4 mV. This means that at full scale, neglecting the effect of offset for
the moment, the measurement would be within 4 mV of the actual value. Note that gain error is expressed as a
ratio. Values near ±FS (±10 V) are more affected from an absolute voltage standpoint than are values near mid-
scale, which see little or no voltage error.
Combining these two error sources in Figure 10, we have a plot of the error band of the USB-1608FS at ±full
scale (±10 V). This plot is a graphical version of the typical accuracy specification of the product.
The accuracy plots in Figure 10 are drawn for clarity and are not drawn to scale.
Figure 10. Error band plot
