AMA Instruments The GC 5000 BTX, Operating Manual, Page: 96 / 152

Operating Manual GC 5000 BTX; Version 5 – 11/2010 94
• The column “ Fit Type” specifies the kind of calibration curve that will be
fitted to the data points. The column “ Origin” specifies whether the
calibration curve will ignore the origin, or it will be forced to pass through
the origin, or it will be extrapolated to the origin.
The “fit type and origin settings” together determine the number of
distinct (not replicate) data points that must be present. This table
shows the minimum number or data points required for each choice of
fit type and origin.
Type of fit Ignore or Extrap Zero Force Zero
Point-to-point (PTP) N/A 1
Linear 2 1
Quadratic (Quad) 3 2
Cubic 4 3
Power N/A 2
•
The column called “ Quant ” (quantification) determines which peak
property is taken as the source of the data points. The parameter are
height, area, multipeak height, and multipeak area.
Note : The first two parameters height and area are the most frequently
used. Area usually gives more reproducible results than height for well-
resolved peaks. However, when peak separation is poor, “height” can be
more accurate than “area”.
Special case of quantification:
The two other quantification types - multipeak area and multipeak height
- base the response on the sum of the areas or heights of all of the
peaks that fall within the component’s search window.
Note : These types of quantification are useful in aggregate hydrocarbon
analysis when you want the sum of all peaks in a window.
•
The columns “ Level amount ” and “ Level Response ” occur in pairs,
one for each level in the calibration file.
.