The Pharmaceutics and Compounding Laboratory
Accuracy in Measurements

Guidelines for Selecting Liquid Measurement Devices

  • Always select the smallest device (graduate, pipet, syringe) that will accommodate the desired volume of liquid. This will minimize the potential for errors of measurement associated with misreading the scale.
  • Use a graduated pipet, syringe, or calibrated dropper to measure/deliver volumes <1 ml.
  • Remember that oily and viscous liquids will be difficult to remove from graduates and pipets, and at best require long drainage time. Consider using a disposable syringe instead, or better yet, measuring by weight rather than volume.
  • Never use prescription bottles, nonvolumetric flasks, beakers, or household teaspoons as measurement devices, unless you calibrate it yourself.
  • When small (<5 ml) or very accurate doses are required, provide the patient with a calibrated dropper, oral syringe, or similar device to ensure proper dosing.