Waters 2489, Operator'S Manual

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1-8 Theory and Principles of Operation
The filter time constant adjusts the filter response time to achieve an optimal
signal-to-noise ratio. Selecting Other and entering a value of 0.0 disables all
filtering.
Lower time constant settings produce these effects:
• Narrow peaks with minimal peak distortion and time delay
• Very small peaks become harder to discriminate from baseline noise
• Less baseline noise is removed
Higher time constant settings produce these effects:
• Greatly decrease baseline noise
• Shorten and broaden peaks
The software includes fast or normal filtering constants at each data rate that
are appropriate for high speed or high sensitivity applications respectively.
The following figure shows the relationship between increased filter time
constant and absorbance.