Abstract: A high pressure switch works to protect the air conditioner (a/c) compressor from operational conditions, and now we also can protect the whole a/c condenser unit (outdoor unit) from theft and vandalism. The safeguard can be accomplished by installing another high pressure switch on the high pressure liquid line or close to the a/c indoor air handler as shown and wired to the central box of the alarm system.

Abstract: A device for detecting vacuum loss in a vacuum breaking apparatus that includes an enclosure having a first part at least partially of insulating material, closed at its opposite ends by end-plates, and housing fixed and mobile electrodes. A second part of the enclosure is insulating material at least partially around the first part, this second part is an over-molding of electrically grounded conductive shielding at least a part of its outer surface. This first strip of over-molding faces both the first part and one of the electrodes, thereby providing two capacitances in series, namely, a vacuum capacitance between the electrode and the inner surface of the first part, and a solid capacitance between the inner surface of the first part and the first strip, and means for measuring change of current value in the first strip, which corresponds to a vacuum loss inside a vacuum breaking apparatus.

Abstract: The present disclosure provides for systems and methods for fabricating sensing and/or control device assemblies, e.g., a dual pressure switch sensing and/or control device, a dual temperature switch sensing and/or control device or the like. More particularly, the present disclosure provides for systems and methods for fabricating sensing and/or control device assemblies (e.g., dual switch sensing and/or control device assemblies) with adjustment features and/or functionalities for switch calibration and/or adjustment. In one embodiment, the present disclosure provides for systems and methods for fabricating sensing and/or control device assemblies (e.g., dual switch sensing and/or control device assemblies) with rotary adjustment features/functionalities wherein the switches of the sensing device may be calibrated or adjusted via the rotary adjustment features/functionalities.

Abstract: A storage system for material containers provides a readable ID distinguishing each container, and includes a scale that weighs containers, so that the system can distinguish between containers that are sufficiently loaded to be effective and containers that are insufficiently loaded. The system preferably includes storage for containers held in contact with readers of the container IDs. This allows a controller to keep track of containers checked out for use and returned for storage, and to identify containers that have been discharged.

Abstract: An overfill probe is utilized in each compartment of a multi-compartment transport tanker and has a depending sensing tube for detecting liquid overfill conditions. An overfill detector is within the bottom end of the probe tube and is thus protected from damage. Internal damage to the probe and malfunction of the system also precluded by connecting the exposed cap of the probe to the detector by a longitudinally extensible, stretchable cable extending through the tube to the detector, or a circuit board may be retained within the depending tube. Additionally, a thermistor socket and an optic socket are provided which are part of the overfill protection system, each having contact connections that may be readily replaced when worn without removing or replacing the wiring within the socket assembly.

Abstract: A RF resonator for sensing a physical or an environmental parameter includes a substrate having a substrate surface. A polymer-derived ceramic (PDC) element is positioned on or within the substrate surface. The RF resonator has a resonant frequency that changes as a function of the physical or environmental parameter. A system for wirelessly sensing at least one physical or environmental parameter includes at least one RF resonator and a wireless RF reader located remotely from the RF resonator for transmitting a wide-band RF interrogation signal that excites the RF resonator. The wireless RF reader detects a sensing signal retransmitted by the RF resonator and includes a processor for determining the physical or environmental parameter at the location of the RF resonator from the sensing signal.

Abstract: An enhanced dive computer functionality providing a diver positioning system integrated into a dive computer and a modified Display Integrated Vibrating Alarm device controlled by the dive computer to allow for decompression integrated guidance and a buddy signalling device. The diver positioning system allows for automatically determining the diver's position by tracking the diver's location in three dimensions within a water column, or portion of the body of water in which the diver operates bounded by the surface and the maximum dive depth, during a dive. A modified Display Integrated Vibrating Alarm allows for guiding a diver through a controlled decompression ascent and a method for automatically warning companion or nearby divers of imminent danger of injury or death to a subject diver.

Abstract: The invention describes a pressure detection system for a pressure cooker, having a sensor (17) for detecting a pressure prevailing inside the pressure cooker by means of measured values, a computer unit (16) connected to the sensor (17), and a display (3, 4), wherein the computer unit (16) is designed to evaluate the measured values supplied by the sensor (17) and to establish whether at least one first threshold value (S1) has been reached. In order to indicate use-related wear, the computer unit (16) is further designed to continue a counter when the measured value reaches the first threshold value (S1) and to output a notification on the display (3, 4) when a predefined value of the counter is reached.

Abstract: A dangerous level of gas safety monitor for indicating a level of a target gas in an atmosphere comprising: a sol-gel layer comprising a first phosphorescent material, exposed to the atmosphere; a light source enabled to stimulate the phosphorescent material; a detector enabled to detect light emitted by the phosphorescent material; a pressure sensor to determine the pressure of the atmosphere; a processor enabled to determine relative phase shift or time delay between the detected light emitted by the phosphorescent material and the emitted light of the light source, wherein the monitor is configured to provide an output indicative of a dangerous level of the target gas in the atmosphere, the output based on the determined pressure and relative phase shift or time delay.

Abstract: A comparative pressure monitoring instrument (10) houses a switch (14) having first and second ports (18) and (20), and a high flow impedance 16. The ports (18) and (20) are in fluidal communication with a first pressure source (72) and a second pressure source (82) respectively. The impedance (16) is coupled (i.e. shunted) across the switch ports (18) and (20) and the first and second pressure sources (72, 82). The switch (14) switches between a first state characterised by a pressure differential across the impedance (16) being less than a preset level and a second state characterised by the pressure differential across the impedance (16) being equal to or greater than the preset difference. Any difference in pressure between the sources (72) and (82) will cause an air/gas flow through the impedance (16) and thus a pressure drop across the impedance (16).

Abstract: An alarm color plate structure of a micro-differential pressure gauge includes a transparent casing. The transparent casing has a slot which is located corresponding to the range of movement of a pointer or a scale plate. An alarm plate is provided in the slot. The alarm plate has a plurality of areas with different colors or marks for the user to know whether the position and the value of the pointer are normal or not.

Abstract: A system and method for detecting a leak or structural defect in a tank are provided. The system includes a removable test plate to seal an opening in a tank to be tested with all other openings in the tank to be sealed. The system also includes a motor-driven blower or other vacuum-generating device coupled to a first opening in the test plate. When the blower is activated, it generates a vacuum inside the tank of a predetermined value. A vacuum-monitoring device is coupled to a second opening in the test plate and monitors the vacuum in the tank. A leak or structural defect in the tank is indicated if the vacuum decreases from the predetermined value by more than a predetermined differential within a predetermined time.

Abstract: A modular device for determining attributes of a substance stored in a container having a sensing module, a transmitter module and a power source module. The sensing module is capable of sensing attributes of a substance and providing an output. The transmitter module is configured to transmit an output of the at least one sensing module when operably coupled to the sensing module. The power source module is capable of being operably connected to the sensor module and the transmitter module to power the sensor module and the transmitter module.

Abstract: A method for monitoring the health of a compressor of a gas turbine is disclosed. The method includes receiving a plurality of turbine data points, wherein the plurality of turbine data points may include one or more operating parameters, at least one of a computer discharge temperature (CTD), and one or more performance parameters. The plurality of turbine data points may be categorized based on the one or more operating parameters. A statistical variability measure of at least one of the CTD and the one or more performance parameters may be computed for each of the plurality of bands. An alarm indicator may be computed based on the at least one statistical variability measure. The method may also include combining two or more of the operating parameters, the CTD and the performance parameters using sensor fusion techniques. The alarm indicator may be computed based on the combined parameters.

Abstract: The invention relates to a method for measuring and controlling a fluid flow in a pipe system for liquid transport, such as oil flow during buoy loading, wherein there in each end of a the pipe system is spliced in a sensor (1) consisting of a pipe section (2) with a reinforced rubber bellows (3) positioned as a restriction within the transport pipe. The rubber bellows (3) is forced radially outward when there is oil flowing through the transport pipe, and compresses a gas filled volume in a pressure vessel (4) via a pipe connection (4B) in communication with an annulus (5), and a pressure transmitter (6A/B) gives signals to a control system (7).

Abstract: The present invention comprises methods for testing the valve seating integrity of a valve. The valve components that determine valve seating integrity are typically a valve seat and a valve closing element that engages the valve seat to close the valve. Examples of the test method described herein respectively test valve seating integrity during opening of the valve and during closing of the valve, and do so in all instances without interrupting the operation of a process control system that includes the valve, without isolating the valve, and without relying on user analysis.

Abstract: A processor incorporated into an alarm system which includes a PC board supporting a first component for output characteristics including a strobe light and/or audible siren. A second component is integrated into the PC board for providing power and for communicating with first and second locations associated with a conduit line to be monitored, with a third component providing the visual or audio output. The second component connects to an identically constructed PC board located in a remote succeeding alarm. The alarm is capable of monitoring at least one of an electrical conductivity or a fluid pressure condition contained within the conduit lines.

Abstract: Described is drug infusion device with one or more vents that permit the passage of gas between the exterior and interior of the device's housing. In one embodiment the device may include multiple interior chambers of differing volume and pressure sensors placed between them, while vents to ambient pressure are included in each chamber. According to this exemplary structure, the readings from the pressure sensor may be used to determine malfunctions in the venting of the device and/or changes in pressure that could cause the unintended delivery of medication.

Abstract: This disclosure describes systems and methods for reducing nuisance alarms associated with monitoring non-physiological parameters in a ventilatory system. Non-physiological parameters may include, but are not limited to, parameters that are internally monitored by the ventilator based on pre-configured ranges dictated by the manufacturer, by an applicable protocol, or by the clinician. Embodiments described herein seek to mitigate nuisance alarms by basing alarm conditions, at least in part, on an integral threshold such that an alarm is not generated when a monitored parameter briefly falls outside an acceptable range by a slight degree, but such that an alarm is generated when a monitored parameter falls outside an acceptable range by a more significant magnitude and/or duration.

Abstract: System for monitoring oil level and detecting leaks in power transformers, reactors, current and potential transformers, high voltage bushings and the like, notably for a system that through the use of sensors and other electronic components measures and monitors transformers and similar equipment in real time, filled with insulating oil, with greater precision and without need for floats or mobile mechanical parts, while presenting countless facilities in the sense of making level monitoring more reliable and safer, highlighting the level error calculations, oil leak detection alarm, excess oil detection alarm during the equipment filling process and calculation of tendencies of evolution for levels among other facilities.

Abstract: A filter monitoring device which detects variances in pressure of fluid flowing through a filter element in a filter assembly includes (1) an indicator for conveying data of changes in the differential pressure of the fluid in the filter assembly and (2) a temperature sensor for transmitting data showing any changes in temperature of the fluid being filtered. A microcontroller converts data received about changes in differential pressure and temperature sensing means to digital format and transmits the data along two differential digital lines to a driver and output connector.

Abstract: A holographic occlusion detection system has a holographic label placed onto a sensing portion of a pressure sensor connected to infusion tubing. The sensor at the sensing portion can have a relatively thin wall section and may be wider and flatter than a normal cross section of the tubing. The label is then illuminated by a polychromatic light source, and the light reflected off the holographic label is then received by a photodetector. Pressure changes within the tubing cause a change in orientation of the light holographic label, thereby resulting in a shift in the peak wavelength of the light sensed by the photodetector. This wavelength shift can then be calibrated to the swelling of the sensing portion so that pressure within the line can be calculated. In another variation, monochromatic light is reflected off a holographic label, and pressure changes are detected by measuring the amplitude of the reflected light.

Abstract: It is an objective to appropriately assure a function of limiting use of appliances that cause changes in quantities of gas used.

Abstract: A burst indicator (24) for use in a rupture disc assembly (12) is provided. The burst indicator (24) comprises a non-electrically conductive material having an outer annular portion (66) and an inner section (68) joined to the outer portion by a pair of bridge features (70, 72). A circuit comprising electrically conductive segments (78, 80) is located on the burst indicator (24) and can be used to monitor the integrity of the rupture disc (20). One electrically conductive segment (78) is located on the outer annular portion (66), and another electrically conductive segment (80) extends across the bridge features (70, 72) and inner section (68). Upon rupture of the rupture disc (20), one of the bridge features (72) carrying an electrically conductive segment (80) severs thereby opening the circuit.

Abstract: A syringe drive device 11 includes a fixing section 15 fixing an outer tube 14, a movable holder 16 holding a plunger 13, and a drive section 42 driving the holder 16 along an axis of the plunger to push and pull the plunger with respect to the outer tube 14. An internal pressure detector 18 has a positive pressure detection switch 63 detecting an internal pressure of a syringe 12. A determination section 41 determines issue of an alert when the holder 16 is stopped and the positive pressure detection switch 63 is ON. A display section 19 is lit to indicate the alert when the determination section 41 determines issue of the alert.

Abstract: An HV-ECU performs a step of detecting an atmospheric pressure, a step of calculating a maximum value of a boost voltage corresponding to the atmospheric pressure by using a map, and a step of setting the maximum value as a system voltage value and controlling a DC/DC converter. Moreover, the HV-ECU may calculate a resistance value of a gate resistance of a switching element corresponding to the atmospheric pressure by using the map and control the gate resistance to achieve the set resistance value.

Abstract: A method, computer program product, and infusion pump assembly for determining a first rate-of-change force reading that corresponds to the delivery of a first dose of an infusible fluid via an infusion pump assembly. At least a second rate-of-change force reading is determined that corresponds to the delivery of at least a second dose of the infusible fluid via the infusion pump assembly. An average rate-of-change force reading is determined based, at least in part upon the first rate-of-change force reading and the at least a second rate-of-change force reading.

Abstract: A rotation speed information detection apparatus, including: a wheel sensor for detecting passage of teeth of a gear provided in association with tires of a vehicle; a number-of-teeth calculation means for calculating the number of teeth of the gear passed per a sampling cycle set in advance; and a wheel speed calculation means for regularly calculating rotation speed information of the tire with using the number of teeth calculated. The number-of-teeth calculation means is configured to use a ratio between time information at the point and a remaining time until the time at which the next sampling cycle is started is reached to thereby calculate the number of remaining teeth to calculate the number of teeth passed during the sampling cycle.

Abstract: The invention discloses devices and methods for identifying a diver in distress and initiating a rescue response. Specifically, embodiments of the present invention allow for identification of a diver who is not breathing properly and in response giving local stimuli to allow the diver to response. Should he/she not respond, the instant invention will initiate steps to bring the diver back to the water surface and alert others as to his/her need of assistance.

Abstract: A fluid level sensor for generating a warning upon, e.g., low fuel conditions in a vehicle gas tank. A vacuum conduit is disposed in the tank. The vacuum conduit has first and second vacuum openings and an actuation opening into which the fuel pump can pump fluid through a Venturi conduit to induce a vacuum. A first conduit extends from the first vacuum opening to a vacuum sensor outside the tank and a second conduit extends from the second vacuum opening. The second conduit extends down into the tank and terminates in an open end. When fluid in the tank drops below the opening the vacuum sensor senses a change in vacuum in the tank, triggering a low level alarm.

Abstract: A highly sensitive low loss and low flow fluid flow switch is coupled with an automatic timer and/or optional transmitter to indicate the flow of gas to an appliance and to automatically start a reminder timer to turn the appliance off. After a preset time limit has expired, the timer either sounds an alarm or wirelessly triggers an alarm in a remote location. The receiver portion of the wireless timer may be mounted directly to the appliance (grill handle), so that the timer automatically resets when activity (cover opening or closing) is detected, indicating the appliance is still in use. An alarm can also be configured to sound when the grill is attempted to be ignited with the cover closed, thereby avoiding a potential explosion. A biasing attraction magnet is incorporated in the fluid flow switch to offset either the force of gravity or a return spring in order to extend performance to low pressure and low flow applications.

Abstract: A cost effective manometer is realized for accurately measuring back pressure in all types of vents and ducts. Common back pressure can be caused by restrictions, such as lint or soot buildup. The manometer consists of a main body having two reservoirs for storage of measuring fluid. The first reservoir contains measuring fluid during transit eliminating the need for end user to manually fill manometer prior to first use. Measuring fluid is transferred to second main reservoir prior to initial use. The second reservoir contains an adjustable bladder or plunger for obtaining a zero reading prior to measurement. The manometer can be used on all types of vents and ducts where positive or negative pressure exists. The manometer can be used for measuring positive or negative pressures as well as differential pressures.

Abstract: Indicator devices and systems for explosion-proof enclosures are described. The indicator devices include a sleeve coupled to a dome-like transparent member by a connector body, at least one conductive contact positioned in the sleeve, a piston responsive to an increase in pressure and positioned in the sleeve, and an indicator. The indicator can be a light source positioned in the transparent member or an alarm external to the indicator device. Upon an increase in a pressure in an enclosure to which an indicator device is attached, the piston shifts and contacts the at least one conductive contact and permits the completion of an electrical circuit from a power source to the indicator. The indicator systems include an indicator device coupled to an explosion-proof enclosure.

Abstract: A method, computer program product, and infusion pump assembly for determining a first rate-of-change force reading that corresponds to the delivery of a first dose of an infusible fluid via an infusion pump assembly. At least a second rate-of-change force reading is determined that corresponds to the delivery of at least a second dose of the infusible fluid via the infusion pump assembly. An average rate-of-change force reading is determined based, at least in part upon the first rate-of-change force reading and the at least a second rate-of-change force reading.

Abstract: A system detects whether a pneumatic surgical instrument is attached to a surgical system. A drive valve has an input for connection to a source of pressurized air, an output for connection to the surgical instrument, and an exhaust for exhausting pressurized air during operation of the surgical instrument. A pressure transducer in communication with the exhaust senses a pressure profile of air flow from the exhaust. A first sensed pressure profile indicates that the surgical instrument is connected to the output and a second sensed pressure profile indicates that the surgical instrument is not connected to the output. A detection circuit connected to an output of the pressure transducer detects whether the surgical instrument is attached to the surgical system based on the sensed pressure profile.

Abstract: Disclosed is a portable alarm apparatus (10) comprising an adhesive suction mechanism (12), a device (3) for monitoring the suction pressure, a device for generating a negative pressure (2), which is connected to the adhesive suction mechanism (12) and maintains the negative pressure in the adhesive suction mechanism (12) substantially constant at a preset value, and an alarm control device (21) that generates an alarm signal when the suction pressure falls below a predetermined threshold value when the preset negative pressure can no longer be maintained.

Abstract: A system includes a fire extinguisher station having a number of sensors to detect various predetermined conditions that can be communicated in alarms to a central station. The central station receives alarms from the fire extinguisher and determines whether to contact emergency personnel and/or building maintenance personnel. Other items of emergency equipment can be included in the system for improved detection and response to emergency conditions.

Abstract: Embodiments of the invention include a system and method for controllably delivering hydrocarbon gas to a hydrocarbon gas-fueled device. According to one embodiment, a valve having an open state and a closed state is used to control the flow of hydrocarbon gas from a pressure vessel to a supply line. A hydrocarbon gas sensor detects airborne hydrocarbon gas and generates a signal in response. A controller automatically moves the valve to the closed state in response to the signal from the hydrocarbon gas sensor while the valve is in the open state. The controller automatically releases liquid sealant to the supply line in response to a continued signal from the hydrocarbon gas sensor after at least attempting to move the valve to the closed state.

Abstract: A transceiver includes a receiver, a signal strength determiner, and a controller. The receiver receives a trigger signal transmitted by a triggering device; the trigger signal indicates both a signal strength range and a command. The signal strength determiner determines the strength of the trigger signal received by the receiver. The controller is configured to: 1) determine whether the strength of the trigger signal determined by the signal strength determiner is within the signal strength range indicated by the trigger signal; 2) and perform a task in accordance with the command indicated by the trigger signal only when the strength of the trigger signal is within the signal strength range.

Abstract: An alarm system for an AC assembly having an exterior located condenser supplied by a pressurized refrigerant system flowing between interior and exterior locations of a structure. A power source supplies an alarm panel at interior locations of the structure. A normally closed fluid pressure switch is electrically coupled between the power source and alarm panel and is maintained in an open and fluid communicating position upon detecting a continuous inlet fluid pressure. The pressure switch recloses upon sensing a decrease or loss of pressure, at which point a relay communicating closes to complete an electrical circuit between the power source and alarm panel. An alarm output in communication with the alarm panel responds to the closing of the relay to issue an alarm condition.

Abstract: A gas measurement apparatus can comprise a sensor and a processor, in an example. The sensor can measure a pressure condition of a gas tank, in an example. The processor can select at least one light source, the light source can be positioned or be of a distinct color to indicate a corresponding level of gas remaining in the tank when illuminated. The level of gas can be based on the measured pressure. Banks of high intensity LEDs can allow visually discernable colors at a significant distance underwater. A visual beacon mode can be included. An alphanumeric pressure readout mode can be included. A depth sensor can be included.

Abstract: An improved pump, reservoir and reservoir piston are provided for controlled delivery of fluids. A motor is operably coupled to a drive member, such as a drive screw, which is adapted to advance a plunger slide in response to operation of the motor. The plunger slide is removably coupled to the piston. A method, system, and an article of manufacture for automatically detecting an occlusion in a medication infusion pump is provided. The electrical current to an infusion pump is measured. Based on a series of measurements of one or more variables, the infusion pump detects whether there is an occlusion in the system.

Abstract: A gas measurement apparatus can comprise a sensor and a processor, in an example. The sensor can measure a pressure condition of a gas tank, in an example. The processor can select at least one light source, the light source can be positioned or of a distinct color to indicate a corresponding level of gas remaining in the tank when illuminated. The level of gas can be based on the measured pressure.

Abstract: A method and apparatus are disclosed for determining a flow rate in a topical negative pressure (TNP) system. The method includes the steps of determining a pumping speed associated with a pump element of a TNP system, determining a pressure associated with a flow path associated with the pump element, and determining flow rate in the flow path responsive to the pumping speed and flow rate.

Abstract: A water leakage monitoring system including a water leakage position estimator which includes a periodic data acquiring unit for fetching predetermined-period flow rate pressure data stored in a monitoring device, and for fetching a signal related to a flow rate change and pressure changes expecting a water leakage reaction time calculating unit for calculating a pressure reaction time lag between two pressure changes, a pressure propagation velocity estimating unit for estimating a pressure propagation velocity using the pressure reaction time lag and a distance between two pressure gauges located in a water distribution block stored in a pipeline network map data, and a flow rate change position estimating unit for receiving a signal related to the flow rate change, and estimating a flow rate change position using pressure propagation velocity and a flow meter and pressure gauge locating positions of the pipeline network map data.

Abstract: Pressure fluctuations are sampled at fixed time intervals and subjected to arithmetic processing, using as a trigger the event (or a sign temporally close to that event) of the reverse motor rotation for the backlash correction, thereby discriminating normal suction from suction of sample liquid with undesirable air bubbles.

Abstract: A medication safety system includes a panel mounted to an IV pole above a multi-channel infusion pump also mounted to the IV pole. The panel includes multiple RFID readers for reading the RFID tags placed on each of the medication containers mounted to the panel. The pump includes a controller that communicates with the RFID readers at the panel to receive the information read by the RFID readers and automatically program the respective pump channel. A verification program verifies that the medication delivery information from the containers matches the patient identified for the pump and the programming parameters of the pump fall within acceptable ranges. In another aspect, the panel contains multiple vibration devices to impart vibrations to the medication of each of the containers mounted to the panel. Those vibrations are sensed by the particular pumping channel to confirm that the correct channel has been programmed for that medication.

Abstract: A pressure and prevacuum testing system for an AC system in a vehicle includes an air pressure source for pressurizing a cooling circuit of the AC system to a predetermined high pressure threshold and a vacuum source for prevacuuming the cooling circuit either to a predetermined prevacuum low pressure level or for a predetermined time period. The system also includes a pressure gauge for operatively measuring a pressure level in the cooling circuit. A controller is operatively connected to the air pressure source, the vacuum source and the pressure gauge. The controller compares the pressure level as measured by the pressure gauge to the predetermined high pressure threshold during a pressurized test of the cooling circuit and to the predetermined prevacuum low pressure level during a prevacuum test of the cooling circuit to determine if leaks are present in the cooling circuit.

Abstract: A system and method for detecting cavitation in pumps for fixed and variable supply frequency applications is disclosed. The system includes a controller having a processor programmed to repeatedly receive real-time operating current data from a motor driving a pump, generate a current frequency spectrum from the current data, and analyze current data within a pair of signature frequency bands of the current frequency spectrum. The processor is further programmed to repeatedly determine fault signatures as a function of the current data within the pair of signature frequency bands, repeatedly determine fault indices based on the fault signatures and a dynamic reference signature, compare the fault indices to a reference index, and identify a cavitation condition in a pump based on a comparison between the reference index and a current fault index.

Abstract: A system that control levels of liquids in reservoirs may include a control component that causes a compressor to pump gas through a tube extending in a liquid in a reservoir to an air bell for a predetermined amount of time responsive to a pump pumping portions of a liquid from the reservoir. The control component may also cause the compressor to pump gas through the tube for a predetermined amount of time responsive to the control component determining that a predetermined amount of time has passed since the compressor was previously operated. The control component may also cause the compressor to pump gas through the tube for a predetermined amount of time, responsive to the control component determining that a pressure sensor component in fluid communication with the tube indicates a possible decrease in the liquid level to at least a predetermined level.