Systems and methods for capacitive fluid level detection, and handling containers

A compartment for storing fluids in an instrument, the compartment comprising:

• one or more holders, wherein each holder of the one or more holders includes:
• a top surface defining one or more openings;
• a bottom wall having an electrically conductive outer surface for connection to an electrical ground or voltage source, wherein the holder is not formed solely of an electrically conductive metal;
• and
• a side wall that extends from the bottom wall to the top surface, the side wall including an electrically conductive side surface that is contiguous with the electrically conductive bottom surface of the bottom wall,
• wherein each holder of the one or more holders defines one or more receptacles, and wherein each receptacle of the one or more receptacles extends between an opening of the one or more openings and the bottom wall;
• and
• one or more containers containing a fluid, wherein each container of the one or more containers is (a) positioned in a receptacle of the one or more receptacles, and (b) is configured to receive a fluid transfer device adapted for capacitive fluid level sensing, and wherein at least one of the one or more containers includes an electrically conductive seal that the fluid transfer device passes through when the fluid transfer device enters the container.

An instrument configured to analyze one or more samples, comprising:

• one or more holders for supporting one or more containers of fluid, wherein each holder includes:
• a top surface defining one or more openings;
• first and second side walls, wherein at least one of the first and second side walls comprises a first electrically nonconductive portion and a first electrically conductive metal coating outer surface (i) affixed to an outer surface of the first electrically nonconductive portion, (ii) forming an outer surface of the at least one of the first and second side walls, and (iii) configured to be connected to an electrical ground;
• one or more receptacles, wherein each receptacle of the one or more receptacles depends from an opening of the one or more openings towards the bottom wall, and wherein each receptacle is configured to receive at least one container of the one or more containers;
• a bottom wall comprising a second electrically nonconductive portion and a second electrically conductive metal coating (i) affixed to an outer surface of the second electrically nonconductive portion, (ii) forming an outer surface of the bottom wall, and (iii) configured to be connected to the electrical ground or a voltage source;
• and
• a fluid transfer device adapted for capacitive fluid level sensing, wherein the one or more containers are accessible by the fluid transfer device.

A method of detecting a fluid level in a container including a fluid, comprising:

• positioning the container in a receptacle of a holder, wherein:
• the holder comprises:
• a bottom wall having an electrically conductive outer surface for connection to an electrical ground or voltage source;
• a top surface defining one or more openings;
• a side wall that extends from the bottom wall to the top surface, the side wall including an electrically conductive side surface that is contiguous with the electrically conductive bottom surface of the bottom wall, and
• one or more receptacles including the receptacle, wherein each receptacle of the one or more receptacles depends from an opening of the one or more openings towards the bottom wall, wherein the receptacle is configured to receive the container, and wherein the holder is not formed solely of an electrically conductive metal, and
• the container is positioned such that a bottom surface of the container is disposed on, or is positioned proximate to, the bottom surface of the holder;
• and
• inserting a fluid transfer device having a probe tip configured for capacitive fluid level sensing into the container to detect a level of the fluid in the container.

A method of extracting fluid from a container, comprising:

• positioning the container in a receptacle of a holder, wherein the holder comprises:
• a bottom wall having an electrically conductive outer surface for connection to an electrical ground or voltage source;
• a top surface defining one or more openings;
• a side wall that extends from the bottom wall to the top surface, the side wall including an electrically conductive side surface that is contiguous with the electrically conductive bottom surface of the bottom wall, and
• one or more receptacles including the receptacle, wherein each receptacle of the one or more receptacles depends from an opening of the one or more openings towards the bottom wall, wherein the receptacle of the one or more receptacles is configured to receive the container, and wherein the holder is not formed solely of an electrically conductive metal,
• inserting a fluid transfer device having a probe tip configured for capacitive fluid level sensing into the container;
• detecting a level of the fluid in the container using the probe tip;
• and
• extracting fluid from the container using the fluid transfer device.