Our syringes came in! Over twenty individually packaged syringes, ready for measurement. After combining them with the syringes we already had and tossing duplicates, we were left with an even 25 syringes for our data. Not even close to the ~100 we were initially looking for, but it’ll do.

Before measuring all our syringes, we needed to fix the Kasupe’s potentiometer to get some useful data out of it. With a pair of needlenose pliers, I painstakingly adjusted the potentiometer manually until it was reading between zero and one at the bottom. Miraculously perfect! We quickly closed the Kasupe and agreed to never open it again, for fear of disrupting the sensor.

I journeyed long and hard to find the legendary Spreadsheet Wizard, who gave me his blessing to design the new data sheet. I created mini documents, all feeding in to a main average measure sheet , which in turn fueled all the data analysis sheets. Everyone took their measurements, and out popped useful charts and very nice numbers! It’s really not that much, but it’s a baby step toward taming the beast that is Excel.

The data was very good; we found a ridiculous correlation between outer diameter and inner diameter, with an R² of 0.997. I mean, this is totally expected: inner diameter should correlate with outer diameter. We just didn’t expect it to be this good. Fortunately, this makes our job a lot easier. The potentiometer should be able to give us a good outer diameter, which we can turn into a good inner diameter, which means we can get a good flow rate!

The only issue is that the potentiometer doesn’t move in a linear fashion – it rotates. This means its output doesn’t linearly correspond to outer diameter. What do we do? Interpolation! A fancy word for connecting dots, we’ll just draw a line based on the data that we do have and use that to guess the outer diameter of what we don’t.  Next week, we’re going to measure a bunch of random syringe-shaped things and try to fill in the gaps.