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Teledyne 7300a - NDIR analyzer User Manual

Page 34

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3 Start-up and Theory of Operation

Model 7300A

3-8

Teledyne Analytical Instruments

Piece-wise approximation is the method used to linearize the signal, i.e., the
linearizer’s output to input relationship can be graphed as a number of
straight line segments connected together to approximate the desired curve
that would be required to compensate for the nonlinearity of the bench

The points at which the compensation curve changes slope are called
breakpoints. The slope of each segment corresponds to the gain of the
linearizer in that segment, and this gain has to vary according to the input
voltage. This is achieved through software by adjusting a multiplier factor at
each straight line segment. The linearizer has nine specific voltage segments.

NDIR Bench Output

Figure I

Gas Concentration

Figure II

Linearizer Input

Linearizer Output