A sensor for use in a canister for fluid collection, the canister having a canister top and defining a fluid collection chamber. The sensor includes a first electrode and a second electrode. The first electrode includes a first portion and a second portion, wherein the first portion of the first electrode is supported by the canister top, and the second portion of the first electrode is configured to extend into the fluid collection chamber. The second electrode includes a first portion and a second portion, wherein the first portion of the second electrode is supported by the canister top, and the second portion of the second electrode is configured to extend into the fluid collection chamber. The sensor also includes an electric circuit configured to detect an electrical property associated with the first and second electrodes.