I'm trying to replicate the calculation that Chemstation uses to calculate response.

To simplify things I have integrated part of a peak from one data point to the next. I have calculated the area in units of time (secs) x abundance, but it comes out higher than the measured response (my result is 197622 vs measured response of 176993). I have taken into account the fact that the integration baseline does not start and end at zero abundance.

Any other method I try gives a similar result.

Can anyone shed any light on how chemstation calculates the area?

The manual says that the units are counts x msecs, but if I use milliseconds then my result becomes 1000x too high.