When measuring volume, where should the measurement be taken on the plunger piston?

When measuring volume using a syringe, the measurement should be taken at the final edge of the plunger piston. This point represents the accurate volume being dispensed from the syringe. The final edge of the piston aligns with the scale on the syringe, allowing for precise measurement. It ensures that the volume drawn into the syringe reflects the amount intended for administration, which is critical in sterile compounding and medication dispensing to avoid dosing errors.

Taking measurements at other points, such as the top edge or midpoint of the plunger, would result in inaccuracies. The top edge could lead to overestimating the volume, while the midpoint does not align with the calibrated scale, leading to uncertainty in measurement. The bottom edge is also not where the measurement is conventionally taken, as it does not accurately represent the volume that will be administered. Understanding this standard practice is essential for maintaining the integrity and safety of compounded sterile preparations.