Saturday, November 26, 2011

Measuring with Anchor

One of my recent projects involves an electronic weight scale, and I've been using various items for rough calibration. I thought I was onto a "Great Milk Conspiracy" when I discovered that my 1 liter bottles of milk only contained 950 cc. But upon further investigation, it turns out that my trusty Anchor Hocking Company measuring cup (bought from a Walmart, in Hawaii I think) is not accurate! After lots of head scratching, I finally weighed various levels of water on a commercial, precision scale. You can see the data here:

Bottom line, there seems to be an offset to the printed scale - for kitchen purposes let's call it 10 cc. For scientific purposes, I would say don't use this - get an accurate graduated cylinder or beaker instead. Well, at least I have solved the milk mystery. Next, I'm going to solve the rice conspiracy (5 out of 5 bags of 1Kg bags weigh EXACTLY 990 grams)...