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  • Stephen Biss

Maybe the Instrument Is No Longer Linear Enough to Be An "8000C"


Purpose:

To explore the analytical variability of the 8000C as determined by the Alcohol Test Committee during evaluation of the 8000C prior to type approval.

To compare the analytical variability of the individual 8000C used in the subject tests for the client with the analytical variability of the type or class 8000C determined by the Alcohol Test Committee.

To suggest that the instrument in the matter before the Court may no longer be a member of that class or type because it is no longer capable of maintaining the analytical variability of the type or class.

To suggest that the instrument in the matter before the Court may no longer have the linearity of the class or type 8000C because it no longer exhibits the linearity established during evaluation of the type or class.

To establish that we have some evidence, that the linear kind of relationship, the created linear relationship that’s done by means of the calibration curve in terms of the – how the instrument works, in the case before the Court, we’ve got a possible interpretation that the relationship that normally should appear linear, the way that Ms. Martin found...is not linear.

To explain to the Court that creation of the calibration curve during factory calibration or re-calibration of an 8000C instrument takes something which is inherently non-linear and turns the instrument into a measuring device that can be used as if it were linear.

To suggest that if the instrument has lost that capability, over time, through drift, then the instrument ceases to be reliable and ceases to be a member of the type or class 8000C.

To use the ATC evaluations of the 8000C, the CFS 8000C Training Aid, and the Martin paper below to cross-examine a government scientist on linearity of the "approved instrument" before the Court.

#analyticalvariability #typeapproval #linearity #linearizer #calibrationcurve #calibration

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