Mechanics: Calibration, part 1

Self-tutoring about behind-the-scenes considerations: the tutor mentions a case of calibration.

In my recent research of fuel additives, I’ve encountered the idea that, to use some properly, one must be able to measure out specific quantities, perhaps in gradations as small as 5mL. I didn’t, until today, have such capability in the mechanical toolkit. I did, of course, in the kitchen, but surely one isn’t going to use one’s kitchenware to measure out fuel additives (?!).

To get such a thing, I went to the dollar store, and wasn’t disappointed. I bought – for a little more than a dollar – a volumetric device that has marked gradations of 10mL up to 250mL. Yet, the thought occurred to me: can I be sure these gradations are accurate?

Academics are trained to be paranoid: someone who has spent time in a lab probably knows that equipment often needs to be calibrated. For instance, if a scale is always high by 0.300g., that’s okay: one just corrects what it says by that amount, so long as one knows.

I measured about 205mL from a measuring cup, then poured it into the device purchased today, which read exactly 210mL. I continued: 50mL from the measuring cup showed as 44mL on the new device; 100mL as 90mL; finally, 250mL they agreed on exactly.

Likely the new device is accurate enough for my purposes.

Interesting, eh?