I read today that the FAA has extended the timeline in which it will be inspecting all charter operations specifications section A008 for compliance with operational control requirements.
We have three sizes of volumetric flasks to choose from: 100, 250 and 500 milliliters and they feature a single etched line or graduation to denote the fill-to-line at the chosen volume. Each size flask is specifically made for preparing solutions that correspond to its nominal value. For example, a 250 ml volumetric flask is the appropriate choice only when preparing a solution with a total volume of 250 ml.
Transfer the solution to be diluted to the volumetric flask, then fill the volumetric flask to approximately 3/4 of its total volume. DO NOT add a stirring bar to the flask (the volume of the stirring bar has not been included in calibration of the flask), but mix the solution well with a gentle swirling motion. Allow the solution to reach room temperature.