Water in a graduated cylinder can most accurately be measured by:

For aqueous solutions such as water, proper volumetric technique requires placing the graduated cylinder at eye level and reading the bottom of the meniscus to avoid parallax error and obtain an accurate measurement. Reading at the top of the meniscus or holding the cylinder above eye level produces inaccurate results. This technique is standard in compounding and measurement guidance used in pharmacy training.

References (Pharmacy Technician documents/Study Guides):

• USP <795> Pharmaceutical Compounding—Nonsterile Preparations: Accurate measurement and meniscus reading for liquids.

• USP general laboratory technique guidance used in pharmacy education (volumetric measurement best practices).

• PTCB/ExCPT Compounding sections: Use of graduated cylinders and meniscus reading.