Bunching is the means by which the integrator keeps broadening peaks within the effective range of the peak recognition filters to maintain good selectivity.
The integrator cannot continue indefinitely to increase the peak width for broadening peaks. Eventually, the peaks would become so broad that they could not be seen by the peak recognition filters. To overcome this limitation, the integrator bunches the data points together, effectively narrowing the peak while maintaining the same area.
When data is bunched, the data points are bunched as two raised to the bunching power, i.e. unbunched = 1x, bunched once = 2x, bunched twice = 4x etc.
Bunching is based on the data rate and the peak width. The integrator uses these parameters to set the bunching factor to give the appropriate number of data points (see Bunching criteria).
Bunching is performed in the powers of two based on the expected or experienced peak width. The bunching algorithm is summarized in Bunching criteria.
Expected Peak Width | Filter(s) Used |
Bunching Done |
|---|---|---|
0 - 10 data points |
First | None |
8 - 16 data points | Second | None |
|
12 - 24 data points |
Third | None |
16 - 32 data points | Second | Once |
|
24 - 48 data points |
Third | Once |
32 - 96 data points | Third, second | Twice |
64 - 192 data points | Third, second | Three times |