The accuracy of volumetric ware depends on the care used in calibrating it, using the correct type of ware for the application, handling the ware properly and ensuring the ware is clean. Calibration of volumetric ware is usually done at 20°C, and the ware should be used at approximately this temperature. Refrigerated liquids should be allowed to come to room temperature before measuring them. Under normal use and care the calibration of volumetric are will not change. Do not expose volumetric ware to excessive heat.