I got a reply from Derek Walker at djb microtech regarding the ALBA experiment I'd been trying to do.
It turns out my method was more or less correct, and that the calculation functions built into ALBA should have been up to doing the analysis. I used Excel so that I wouldn't have to learn how to make ALBA do the same thing. I will learn when I find the time.
Derek confirmed that there are plans to add the experiment to the ALBA applications on the next disk, and has asked me to send him my data.