Reading a meniscus without guessing

A graduated cylinder is built to deliver. You pour out, a film stays behind, and the tolerance assumes that. A volumetric flask is built to contain. You fill to the line, stopper, and invert. They are different tools.

Bring the mark to your eye. Looking down into a cylinder makes the reading high. For aqueous solutions in clean glass, read the bottom of the meniscus.

Class B cylinders in this catalog are for routine transfers. When a method names Class A, use the volumetric flask and the temperature printed on its neck.