What technique should be used to ensure accurate volume measurement with a syringe?

To ensure accurate volume measurement with a syringe, it is essential to measure at the final edge of the plunger piston. This technique guarantees that the liquid being measured is precisely at the intended volume mark on the syringe.

When you read the measurement at the final edge of the plunger piston, you're accounting for the actual position of the liquid within the barrel of the syringe, which affects the overall volume. This method mitigates potential errors that could arise from different perspectives or placements of the luer tip.

The other techniques involve practices that could lead to inaccuracies. For instance, measuring at the middle of the plunger could introduce variance, particularly if the operator misjudges the liquid level. Taking the measurement while still inserting can lead to a dynamic change in the liquid level, which defies the purpose of a static measurement. Reading the measurement after injecting the liquid is problematic, as it completely disregards the volume that has already been expelled, resulting in a misleading reading of the liquid volume.