Methods and apparatus for chemical delivery are provided herein. In some embodiments, a first reservoir holds a first volume of fluid, receives a carrier gas, and outputs the carrier gas together with vapor derived from the first volume of fluid. A second reservoir holds a second volume of fluid and is capable of delivering a part of the second volume of fluid to the first reservoir. A self-regulating tube extends from the first reservoir to a region above the second volume of fluid in the second reservoir.

Disclosed is a basement sewer drain pump housing that draws fluid from a drain into a housing, the fluid is discharged from the housing and out of the basement. The device comprises a pickup tube having a fluid level sensor, which is placed within a sewer main drain or floor drain. The housing comprises an enclosed volume, a suction tube connected to the pickup tube, a suction pump, and a discharge pump. The pump is activated by a switch controlled by the pickup tube fluid sensor, the fluid is drawn into the housing from the drain and discharged through a discharge pipe. The device operates from outlet or battery and serves as a basement drain pump that prevents fluid and sewage backflow during power outages and plumbing blockages. Another modification provides two donuts to prevent the flow of fluid blocking both the floor drain and the main sewer drain.

An apparatus for detecting an error in the measurement of a water level in a washing machine includes a water level sensor measuring a water level in a washing tub; a water supply and drain device supplying water to the washing tub or discharging water from in the washing tub; and a control unit controlling the water supply and drain device to adjust the water level in the washing tub, and detecting a measurement error of the water level sensor based on a water level change measured by the water level sensor while the water level is adjusted.

Disclosed are a water storage tank and a method for controlling the full water level thereof. The water storage tank according to one embodiment of the present invention comprises: a tank main body for storing water which flows in through a water inlet and discharging water through an outlet; and a control unit for controlling inflow and outflow of water into and from the tank main body, wherein the control unit can change the height of the full water level of the tank main body according to a user's selection or the degree of water discharge from the tank main body.

A method of monitoring a low water volume within a water circulation system is disclosed that includes detecting an auxiliary measurement associated with an ancillary device fluidly coupled with a reservoir of water in a water circulation system and then determining whether the ancillary device is performing under a low water volume operation. The low water volume operation is based upon a comparison between at least the detected auxiliary measurement of the ancillary device and a condition associated with a performance of the ancillary device under the low water volume operation.

A capacitive fluid level sensing arrangement for use in a medical device is provided. The arrangement includes at least one pair of conductive plates configured to increase and decrease the amount of electric charge stored in relation to the level of fluid within a fluid maintaining device, such as a reservoir. The conductive plates are electrically connected to a medical device and are configured to measure the charge stored between the plates and thus sense the fluid level. The electric circuit may communicate the measurement to an instrument host arrangement for operating a pump configured to remove fluid from the reservoir and move the fluid to a collector when the level exceeds a preset upper level amount. The instrument host arrangement may stop operating the pump when the fluid level is reduced to a preset lower level amount.

Fill level monitoring relates to a method for controlling the fill level of a collecting vessel, wherein the collecting vessel could be filled with a dielectric medium. A fill level is monitored by a monitoring circuit with a measuring capacitor, the capacity of which changes steadily in correlation with the fill level, at least beyond a fill level range of the collecting vessel. The method includes: determining a capacity of the measuring capacitor; determining the quality of the measuring capacitor; determining a permittivity of the dielectric medium on the basis of the quality of the measuring capacitor; determining a fill level of the collecting vessel on the basis of the determined capacity of the measuring capacitor and the permittivity of the dielectric medium; and fill level-dependent drainage of the dielectric medium from the collecting vessel.