A liquid level control module comprising an elongated tubular housing immersible through a surface of a liquid and into a bulk volume of the liquid, and first, second, and third electrical switches, and first and second floats movable along the tubular housing. The first electrical switch is disposed within a lower portion of the tubular housing, the second electrical switch is disposed within an intermediate portion of the tubular housing, and the third electrical switch is disposed within an upper portion of the tubular housing. Each of the switches has an open state and a closed state. Motion of the first float relative to the first switch changes its state. Motion of the second float relative to the second switch changes its state, and motion of the second float relative to the third switch changes its state. Thus a two-float module may provide three level control signals.

The invention provides an apparatus, system, and method for detecting a layer of contaminants, such as oil and/or hydrocarbons, on the surface of accumulated water within a confined area that is periodically evacuated by a pump. The detection of contaminant layers may be accomplished through the use of an optical detection system comprising a light source, and a conductive sensor comprising a horizontally-disposed plate and a stilling tube. Dissipation of turbulence and agitation of the accumulated water may be achieved by a stilling tube proximate one or more of the sensors disposed within the stilling tube. Additional sensors may detect high, intermediate, and low levels, and an integrated controller may determine the state of media within the confined area, the system being generally configured to keep the oil or other contaminant within the confined area while continuously and/or periodically pumping water away from the confined area.

A sensor assembly for measuring a level of a liquid includes a measuring section through which a measuring current runs during operation of the sensor assembly and a temperature compensation section. The temperature compensation section compensates a temperature dependent variation of the measuring current within a predetermined operational temperature range.

A sensor assembly that includes a sealed housing. A printed circuit board assembly including a first section that includes processing circuitry is disposed within the sealed housing and a second section that includes detection circuitry extends from the sealed housing. The sensor assembly also includes a conductive target movably coupled to the second section of the printed circuit board to vary net voltage of the detection circuitry as the conductive target moves along the second section to provide an output signal. The processing circuitry detects the output signal and converts the output signal into a linear representation of position of the conductive target in relation to the second section.

A sensor assembly for measuring a level of a liquid includes a measuring section through which a measuring current runs during operation of the sensor assembly and a temperature compensation section. The temperature compensation section compensates a temperature dependent variation of the measuring current within a predetermined operational temperature range.

Disclosed is a detector system for detecting underground anomalies comprising a detector device which includes a fluid chamber which is sealed; a float including a target, positioned within the fluid chamber; and a shielded phase shift proximity sensor configured to detect a distance between the target and proximity sensor, wherein a presence of an underground anomaly is determined based on the detected distance.

A sensor assembly that includes a sealed housing. A printed circuit board assembly including a first section that includes processing circuitry is disposed within the sealed housing and a second section that includes detection circuitry extends from the sealed housing. The sensor assembly also includes a conductive target movably coupled to the second section of the printed circuit board to vary net voltage of the detection circuitry as the conductive target moves along the second section to provide an output signal. The processing circuitry detects the output signal and converts the output signal into a linear representation of position of the conductive target in relation to the second section.

A self-cleaning sensor to determine a level of a liquid includes a tube with an interior coating and a plurality of horizontally aligned, electrically isolated, electrical contacts. The self-cleaning sensor includes the plurality of horizontally aligned, electrically isolated, electrical contacts that each terminate in an outer surface of an interior wall of the tube and are electrically connected to one or more electrical devices in a cap residing on the tube. Additionally, the self-cleaning sensor includes a float that is composed of a low density, low dielectric constant material buoyant in one or more liquids to be measured where each horizontal dimension of the float corresponds to each horizontal dimension of the tube.

A circulating bath (10) including a heater (18) configured to heat a fluid (34) in a reservoir (22). The heater (18) is configured to be operatively connected to a source of power (50) by a control circuit (39) operatively coupled to the heater (18). First and second fluid level sensors (14) (16) are operatively coupled to the control circuit (39), and provide signals indicative of a low fluid condition in the reservoir (22). The control circuit (39) is configured to receive the signals from the fluid level sensors (14) (16), and disconnect the heater (18) from the source of power (50) in response to receiving a signal from either of the first and second fluid level sensors (14), (16) indicative of a low fluid condition.

A self-cleaning sensor to determine a level of a liquid includes a tube with an interior coating and a plurality of horizontally aligned, electrically isolated, electrical contacts. The self-cleaning sensor includes the plurality of horizontally aligned, electrically isolated, electrical contacts that each terminate in an outer surface of an interior wall of the tube and are electrically connected to one or more electrical devices in a cap residing on the tube. Additionally, the self-cleaning sensor includes a float that is composed of a low density, low dielectric constant material buoyant in one or more liquids to be measured where each horizontal dimension of the float corresponds to each horizontal dimension of the tube.