Class B Spout Cylinder
Class A Spout Cylinder
Class B Stoppered Cylinder
Class A Stoppered Cylinder
Measuring cylinders are used for measuring volumes of mobile liquids. For viscous liquids or semi-solids a conical measure is easier to use. There are a variety of types and styles of measuring cylinder, and below is a brief guide to which is appropriate.
For basic measurement of liquids in qualitative work a Class B cylinder is sufficient. Typical usage might be measuring solvents for reactions, making up solutions or adding an excess of a reagent. Used in schools, universities and research laboratories.
For more accurate measurement of liquid a Class A cylinder is appropriate. Class A cylinders are calibrated to half the tolerance of Class B cylinders and each has a unique serial number for traceability. A certificate of accuracy traceable to national standards can be provided if required. Class A cylinders are used in analytical labs, quantative labs, and other controlled environments. They are not suitable for work which requires accuracy of less than 1%. For this a bulb pipette (0.2%) or a gravimetric method (0.0001%+) should be used.
Stoppered cylinders are used for making up solutions where it is important to homogenize the liquid by shaking. They are also useful for measuring volatile solvents where significant evaporation might occur if the liquid is exposed to air. Class B are used for qualitative work and Class A for quantitative work, similar to the spout cylinders above.