Volume of a round bottom segment is calculated incorrectly. The formula for the volume is correct. I wonder why the volume is incorrect and what formula is used by Venus to follow a liquid level during aspiration.

Below is an example of a container consisting of a single rounded base segment of a 60mm diameter and of a 30mm height.

The labware editor provides the correct formula, but a wrong volume: 42.4ml instead of 56.5ml:

@ivmikh - Discussion related to this topic, and other helpful context can be found in this forum post. I am not completely sure as to exactly why the reported volume for a rounded base segment is being underestimated by the labware editor application (compared to the theoretical volume based on face-value geometry), but this volume calculation (from labware editor) is not what VENUS uses at runtime to calculate liquid following, when that is toggled on.

Rather, VENUS does a separate calculation for liquid following distance based off of the starting height of the aspiration and the mixture of container segment geometries the requested volume.

More accurate techniques for using channels to measure and estimate remaining volumes in containers is discussed in the linked thread.

-Nick

It is a pity that Venus doesn’t follow this formula, because the formula in the Labware Editor is correct. Moreover, for a segment with such a large diameter, a meniscus correction is negligible.

I appreciate you have provided a link to a relevant thread. However, the problem persists in this current thread:

Why does the Hamilton Labware Editor report an incorrect volume having got a correct formula for Volume(height)?

@ivmikh - There are proprietary considerations regarding channel and MPH liquid following speed when aspirating/dispensing in complex container segment geometries. I am unaware of any container type or liquid transfer that has proven to be in incompatible with slight deviations in tip submerge depth during portions of liquid following. Please let me know if you are experiencing issues, and we can take measures for support from there.

Regarding the incorrect estimate of volume reported by the labware editor for rounded base container segments, this has been reported to our software team. What I can say is this volume estimate is not used by VENUS outside of the labware editor window you have pointed out. It’s role is mainly to give the user feedback on their container definition, during the definition process.

-Nick