Abstract: Method for fill level measurement with a radar fill level measuring device using the following steps: sending a transmission design with a plurality of frequency ramps, receiving a reception signal per frequency ramp of the transmission signal, saving the reception signals in a memory, performing a first spectral analysis of the reception signals or performing a second spectral analysis of the reception signals, carrying out a second spectral analysis of several output signals of the first spectral analysis at the location of at least one significant reflector in the reception signal or performing a first spectral analysis of several output signals of the second spectral analysis, determining the distances of significant reflectors from the results of the first spectral analysis, determining the fill level echo based on the previously determined information.

Abstract: An apparatus for determining a vertical level or density of a material column including one or more of a granular solid, a wet granular solid, a slurry, and a suspension, the apparatus having a support member; and at least one measurement module, wherein the measurement module includes a support arm mounted to the support member and extending outwardly from the support member; a displacer mounted to the support arm, and a force measurement device configured to measure a force attributable to a mass of the displacer mediated by a buoyancy of the displacer in the material column, wherein the measurement module has a data connection to a data processing unit for transmitting measurement data from the measurement module to the data processing unit to generate level or density information about the material column.

Abstract: Disclosed are an embedded system, a fast 3D camera system based on structured light, and a method for acquiring 3D images using the system. The embedded system includes a pattern generation module for generating the pattern in real time and a camera trigger module for converting a camera synchronization signal into a trigger signal and transmitting the signal to a camera. A transform module for transforming the pattern into a video signal and a communication module for receiving a command for projecting patterns and capturing images may be further included. The fast 3D camera system based on structured light includes an embedded system for generating a pattern in real time upon receiving a command for projecting patterns and capturing images, a projection device for projecting the pattern, and a camera for capturing the image of an object onto which the pattern is projected.

Abstract: An intelligent, automated system for loading agricultural product application equipment is provided in which a control system can determine a necessary amount of product for completing a field operation and can automatically couple with a tendering system to receive such product at an optimal time and location. The control system can determine a current amount of product, a projected amount of product necessary to complete a field operation and a refill amount of product from the current amount and the projected amount, then transmit the refill amount to the tender. The control system can further determine whether a position of the equipment relative to the tender is within a threshold, and whether an intake coupler of the equipment is connected to a supply coupler of the tender, and can control valve(s) to open and close channel(s) for loading fluid into the storage tank.

Abstract: A system for determining the surface structure of an object, the system comprising a first assembly including an illumination source, and a binary mask to generate a binary pattern, the binary mask disposed between the illumination source and a defocusing element to modify the binary pattern to provide a continuously modulated fringe pattern to illuminate the surface of the object.

Abstract: A septic tank maintenance warning system includes a dwelling and a housing mounted in the dwelling. A processor is mounted in the housing and is programmed with a first time comprising a current date and time. The processor is programmed with a second time comprising a future date and time with respect to the first time. The second time defines an alarm time. The second time is resettable to a new second time only between 5.0 hours and 10.0 years forward of the first time when the second time is reset. An alarm is electrically coupled to the processor and is activated when the second time is attained. The alarm is turned on when the second time is attained. The alarm is turned off only when the processor receives a reset code.

Abstract: A fluid sensing system includes a sensing element having a positive temperature coefficient of resistance. The system also includes a switch which is switchable between an open position which prevents current from passing and a closed position which permits current to pass. An inductor is connected electrically in series between the switch electric output and the sensing element and a diode is connected electrically in series between the sensing element and the inductor such that an output of the diode is between the switch and the inductor. A hysteretic controller changes the switch from the open position to the closed position when current passing to the sensing element falls to a lower current threshold and changes the switch from the closed position to the open position when current passing to the sensing element rises to an upper current threshold. A voltmeter measures voltage across the sensing element.

Abstract: A wireless pressure sensor for sensing pressure of a liquid in a tank includes a hermetically sealed housing, at least one sensor, at least one photocell array, at least one communication device, and at least one energy storage device. At least a portion of the hermetically sealed housing has a diaphragm. The at least one sensor within the hermetically sealed housing is configured to sense the pressure of the liquid. The at least one photocell array is configured to receive light and generate power from the light. The at least one communication device is configured to transmit data corresponding to the sensed pressure using wireless radio frequency signals. The at least one energy storage device is configured to store power generated by the at least one photocell array and provide power to the at least one sensor and the at least one communication device.

Abstract: A product runout tracking system for an agricultural implement includes a controller having a memory and a processor, wherein the controller is configured to determine a distance remaining until a storage tank is empty of a product based at least in part on an amount of the product within the storage tank of the agricultural implement, a flow rate of the product from the agricultural implement, a ground speed of the agricultural implement, or any combination thereof. The controller is further configured to determine a product runout location of the product within the storage tank based at least in part on the determined distance remaining and a planned route of the agricultural implement, wherein the product runout location includes a location within the field in which the storage tank is estimated to be empty of the product, and output the product runout location to a user interface for display to an operator of the agricultural implement.

Abstract: A wastewater monitoring system uses a camera in a fixed location in a wastewater pipe. The camera is coupled to a sensor that measures some characteristic of material in the wastewater pipe. The sensor is programmed with one or more alarms that, when triggered, cause the sensor to wake up the camera and command the camera to take one or more photos. Sensor data, such as current time/date, location, and the characteristics of material in the wastewater pipe, is sent by the sensor to the camera, which overlays one or more photos with visible text information corresponding to the received sensor data. The sensor can wake up the camera and command the camera to turn on the camera's Wi-Fi interface, which allows a wastewater control system in a remote location to communicate directly with the camera.

Abstract: A method of fuel gauging includes the use of limited physical probes and a number of virtual probes that are mathematically represented despite having no physical representation. Each probe determines the volume of fuel in a particular section of the fuel tank. The calculation method includes using the attitude of the fuel tank to calculate the rotation of each physical probe, using this information to determine the height of the fuel at each physical probe, and extrapolating the physical height information to determine the position of each virtual probe. Once the information on each physical and virtual probe is obtained, a total fuel volume can be calculated.

Abstract: A multi-probe sender may include a multi-probe having a reed switch arrangement in which reed switches form a level-sensitivity obtaining interval at which a value overlap is prevented in consideration of a resistance-value tolerance range, and having a probe layout forming an intersection interval at which value interference is prevented in consideration of an interval overlap of the reed switches.

Abstract: A method for measuring a fill level of a fill substance in a container with a fill-level measuring device working according to the travel time principle. The fill-level measuring device in measurement operation sends transmission signals toward the fill substance in the container and, based on their signal fractions reflected back in the container, derives echo functions, which give the amplitudes of the signal fractions as a function of their travel time.

Abstract: A probe end device for a cable probe including a measuring cable having a predeterminable cross section is disclosed. The probe end device includes a probe end body having a receiving opening for an end portion of the measuring cable, the receiving opening having a wall, which is set up to provide a progression of an end portion, which is inserted into the receiving opening, of the measuring cable, and the wall further being set up to space apart the end portion, which is inserted into the receiving opening, of the measuring cable from at least one boundary of the probe end body.

Abstract: A system for deriving the operating state of a machine comprises one or more sensors for making available in each case an output value relating to a current parameter of a component of the machine, and a processing unit which is connected to the sensors and is programmed to derive information about the operating state of machine using a model and on the basis of the measured values of the sensors and/or values derived therefrom. The processing unit can be supplied with a state transition matrix, elements of an emission probability matrix for the probability that an observation is conditioned by a certain state, and a vector for describing an input state, in order to derive the operating states of the machine therefrom. The processing unit is programmed to derive elements of the emission probability matrix from the measured values of the sensors.

Abstract: A method, system and computer-readable medium for managing usage of storage tank consumables in a storage tank are provided. This is achieved by receiving and storing by a central server comprising a processor and a storage device, measurements of storage tank consumables from a remote system associated with a storage tank; periodically calculating by the processor usage-based data for generating invoices for storage tank consumables based on sensor measurements representative of an estimated usage of the storage tank consumables; receiving and storing by the central server a fill value representing an actual usage reported to the central server when the storage tank is filled; and reconciling the estimated usage with the actual usage by the processor by summing all estimated usages since a last fill of the storage tank, calculating a difference between the sum of the estimated usages and the fill value, and issuing a debit or credit based on the difference for reconciliation.

Abstract: An obstruction marking method includes generating a first echo curve using an electronic level gauge (ELG) coupled to a tank from a first reflected signal (echo signal) received when a material in the tank is at a first level. The ELG includes a radar-based obstruction detection algorithm stored in a memory coupled thereto. A processor implementing the obstruction detection algorithm identifies at least a first feature in the first echo curve to provide at least one suspected obstruction along with its position (first feature position). A second echo curve is generated from a second reflected signal when the material is at a second level. A third echo curve is generated from a third reflected signal when the material is at a third level. The suspected obstruction at the first feature position is stored in the memory as a verified obstruction with its first feature position.

Abstract: The present invention relates to a radar level gauge system comprising a first receiver branch for converting a reflection signal to a first digital measurement signal, and a second receiver branch configured to convert the reflection signal to a second digital measurement signal. The first receiver branch modulates an amplitude of the first measurement signal according to a first gain function, and the second receiver branch modulates an amplitude of the second measurement signal according to a second gain function different from the first gain function. The radar level gauge system further comprises processing circuitry configured to determine the filling level based on the first measurement signal and the second measurement signal.

Abstract: A fluid level sensor assembly for monitoring a fluid level in a fluid collection canister of a medical waste fluid collection system. The fluid level sensor assembly includes a fluid level sensor configured for monitoring the fluid level in the fluid collection canister and a fluid level sensor cover configured for preventing direct contact between the fluid level sensor and a fluid in the fluid collection canister. The fluid level sensor cover includes a polymeric cap and polymeric sheath extending from the cap. The elongate tubular sheath surrounds an elongate probe of the sensor with the cap positioned at a base of a sensor body of the sensor to prevent direct fluid contact with the elongate sensor probe and the sensor body.

Abstract: A computed-implemented method, a device, and a non-transitory computer readable storage medium are disclosed that can perform a method of visualizing sensor data obtained from a plurality of wells at a well site. The method can include acquiring sensor data from one or more sensors operable to measure conditions of subsystems of each well in the plurality of wells at the well site; determining, by a processor, a visual representation of the sensor data; and causing the visual representation of the sensor data to be displayed in a matrix layout on a visual display, wherein the matrix layout comprises an end row representing a current value of the sensor data and one or more intermediate rows representing a past value of the sensor data.

Abstract: An apparatus, system and method for measuring quantity of a material are disclosed. One or more sensors are used to measure the quantity of the material are measured and error causing parameters are also measured. Error causing parameters are processed by executing one or more correction methodologies to determine a correction output. The quantity of the material is measured by using the correction output. One or values associated with the quantity of the material are measured and displayed. The one or more values are transmitted to a server and informative messages are received from the server.

Abstract: Devices, methods and systems disclosed herein relate to a universal charger which provides a power supply for the charging of OMTP devices and non-OMTP devices based on whether an OMTP mobile communication device or a non-OMTP mobile communication device is connected. A power charging apparatus is provided for charging a mobile communication device. The power charging apparatus includes a connector for connecting to a charging port of the mobile communication device, and a controller coupled to the connector, the controller configured to determine whether the mobile communication device connected to the connector is a non-OMTP mobile communication device or an OMTP mobile communication device, the controller further configured to charge a non-OMTP mobile communication device when a non-OMTP mobile communication device is connected to the connector, and further configured to charge an OMTP mobile communication device when an OMTP mobile communication device is connected to the connector.

Abstract: A well cellar high fluid level alarm includes a control box providing a water-tight enclosure and a alarm control circuitry disposed within the control box. An audible alarm indicator is operably connected to the alarm control circuitry. A visual alarm indicator is operably connected to the alarm control circuitry. A float switch is operably connected to the alarm control circuitry. An electrical power cable is operably connected to the control circuitry and provides electrical power thereto. A control switch is operably connected to the control circuitry and is operable to turn the control circuitry on and off. Operational indicator lamps are operably connected the control circuitry and operates to indicate an on or off state of the control circuitry. The control circuitry operates to operate the audible alarm indicator and the visual alarm indicator upon the float switch sensing a high fluid level.

Abstract: A vibration limit switch system and related method is provided with a piezoelectric transmitting- and/or receiving unit, in operable connection with a membrane that can be put in oscillation, and a mechanical oscillation arrangement that is coupled to the membrane, whereby the piezoelectric transmitting- and/or receiving unit is adhered directly, or via an adaptation layer by an adhesive layer, to the membrane 4. In this improvement, the adhesive layer between the membrane and the transmitting-and/or receiving unit or the adaptation layer has a thickness in an edge area R which thickness is elevated in comparison to a central area Z. This thickness is arranged in differing geometries and amounts to further improve performance.

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: A system is provided to control fluid flow in a wastewater treatment system through wastewater level manipulation. The wastewater treatment system may include a wastewater treatment plant connected to a plurality of pump stations by a main. Each of the plurality of pump stations may include a wet well with a pump therein. The system may include a central server in communication with a sensor to sense a level of wastewater within the wet well. The pump may be automatically moved to an on position when the level of the wastewater in the wet well is at or above a first level and may be automatically moved to an off position when the level of the wastewater in the respective wet well is at or below a pump cutoff level. The central server may systematically manipulate the first level to selectively set the level of wastewater within the wet well.

Abstract: A system of managing product at a location in which a weight-sensing RFID tag is utilized to determine the weight or pressure applied to a substrate and then this information is read by an RFID reader and then transmitted to a data storage repository and processing program for further handling of the data. The data storage repository and processing program may be near the RFID reader or may be remotely located with respect to the RFID reader.

Abstract: The water saving alarm for use with a toilet tank is an accessory that works in conjunction with an existing toilet to provide an audible alarm upon detection of a drop in water level inside of the toilet tank for a predetermined amount of time. The water saving alarm is solely capable of alerting an end user to a continuously running toilet in order for said end user to take corrective action with said toilet. The water saving alarm includes a housing that rests atop of the top, edge of the toilet tank, and from which an air pressure tube descends downwardly inside of the toilet tank in order to detect water level therein. The audible alarm is produced from a speaker located elsewhere on said housing.

Abstract: The present invention provides a method of determining if a fluid level in a transmission is satisfactory. The transmission includes a controller and is coupled to a powered vehicle. The method includes measuring a grade of the surface upon which the vehicle is positioned with an inclinometer and measuring the fluid level in the transmission with a fluid sensor. The method also includes communicating the measured grade and measured fluid level to the controller and determining a fluid level threshold based on the measured grade. The measured fluid level and fluid level threshold are compared and a determination is made if the measured fluid level is satisfactory based on the comparison.

Abstract: Utilizing a sonar system to determine if a structural member of an underwater support structure that is supposed to be filled with air is instead flooded with water. The determination that a supposedly air filled structural member is instead flooded with water provides an indication that the structural member is cracked or damaged, making it easier to find damaged members and effect suitable repair. The sonar system is located a distance from the structural member so that it is spaced from the structural member.

Abstract: This disclosure relates to early detection of low bicarbonate level. In certain aspects, a method includes receiving a first signal from a conductivity detector connected to a line through which a solution of salt concentrate and fluid flows and determining a first conductivity of the solution based on the first signal. The method also includes receiving a second signal from the conductivity detector at a time after receiving the first signal, determining a second conductivity of the solution based on the second signal, and determining whether the second conductivity is less than the first conductivity by at least a threshold amount.

Abstract: Apparatus useful for connecting a drain pan overflow sensor to the evaporator assembly of a ductless mini-split HVAC system includes at least one carrier extending upwardly from the overflow sensor and at least one connector releasably engageable with the carrier and at least one fin and/or evaporator coil tube of the evaporator assembly.

Abstract: Signaling systems are disclosed that indicate a change in an absorbent article, such as the presence of a body fluid. The various different signaling systems disclosed do not include any conductive elements contained on the interior of the article as were required in the past. Instead, the changes are monitored from the outer cover of the article. In one aspect, for instance, a signaling device is provided for sensing and indicating the presence of a body exudate in an absorbent article, the device including a housing and a capacitive sensor disposed within the housing, the capacitive sensor adapted to sense a change in capacitance due to an insult to the absorbent article. The signaling device can include an attachment mechanism for removably attaching the housing to the absorbent article.

Abstract: A system for notifying when a fire extinguisher is discharged or moved uses a device mounted on the fire extinguisher for monitoring one or more conditions. For example, the device may be interconnected with a trigger detecting mechanism otherwise present on the extinguisher or sense a sudden drop in pressure to detect when the extinguisher is activated. An accelerometer may be provided to detect motion. GPS processing can identify the location of the fire extinguisher when an event occurs. When the device detects a change in one or more of the conditions, or needs to send periodic updates of the fire extinguisher conditions, a message is forwarded from the device to a third party clearinghouse via a wireless communication network. The clearinghouse reviews the data, and forwards the data, as may be appropriate, to one or more authorized parties identified in the database.

Abstract: One aspect of the invention is an apparatus including an alarm for alerting an operator to recharge a humidifier, wherein such alarm is generated other than through the use of a humidity sensor. In one embodiment the total work performed during heating and hydrating an insufflation gas is measured and an alarm generated when the total work performed exceeds a particular threshold. In another embodiment, a flow meter is used to measure the total flow of insufflation gas so that when the total flow of insufflation gas reaches a predetermined level an alarm is activated.

Abstract: A fluid leak containment device (20) having a back wall (32), a left wall (38), a front wall (26), a right wall (44) and a base (24) is disclosed. The front wall (26) has a height (74) less than that the height (72) of the back wall (32), the left wall (38), and the right wall (44). The base (24) has plateaus (50) and valleys (52) that direct the flow of a fluid (22) to the front wall (26) if a leak does occur. A sensor (64) may be placed to provide additional auditory or visual alerts when fluids (22) are detected by the sensor (64) in fluid leak containment device (20).

Abstract: A dewatering system includes a selective calibrating sensor circuit configured to receive sensor readings from an electronic sensor, to determine if the electronic sensor is immersed in water, to allow a user to adjust a pump down time in the field, and to generate a control output signal accordingly. The selective calibrating sensor circuit periodically performs a self-calibration when the electronic sensor is not immersed in water to cancel the effect of potential contaminants deposited on the electronic sensor over its operating life. The selective calibrating sensor circuit inhibits calibration when the electronic sensor is immersed in water. In some applications with multiple electronic sensors, the selective calibrating sensor circuit disconnects from one of the electronic sensors before performing the self-calibration. In certain embodiments, a pump control circuit including the selective calibration sensor circuit can be configured to be mounted with a housing of the pump.

Abstract: A marine fuel system and method includes receiving a fuel level signal from a fuel level sensor for a marine fuel tank on a marine vessel and discriminating between condition A comprising an increase in the true amount of fuel in the fuel tank above a given level, and condition B comprising a transient increase in the level of fuel in the fuel tank above the given level due to vessel movement, which may include movement due to waves, rough water, people moving on the vessel, and so on, while the vessel is stationary at a dock or filling station and being re-fueled. An alert signal is output in response to condition A and not to condition B.

Abstract: A fluid volume alarm system is presented. The alarm system has a container for storing fluid, and alarm module coupled to the container for notifying a user or observer that the fluid within the container has reached a predetermined level. The container has at least one exterior wall and defines an interior volume for at least temporary storage of fluid. In one aspect, there are at least two electrodes disposed on an interior portion of the exterior wall of the container and positioned at a position thereon an interior portion of the exterior wall corresponding to a predetermined fluid level at which it is desirable to receive an alarm. The system also has an alarm module configured to alert the practitioner that the fluid has met or has exceeded the predetermined level.

Abstract: A fuel gauge system has a fuel gauge unit, a processing unit, display units, input units, and a GPS navigation system unit with means to connect to other connections and which, by audio and visual aids, informs and alerts an operator of a vehicle of the amount of fuel remaining and range and which allows the operator to manipulate and select and alter the levels, the volume and frequency intervals at which the alerts are sounded, emitted and displayed.

Abstract: A device for monitoring the condition of a fluid receptacle such as one that is gradually filling or emptying is disclosed. The receptacle is attached to a torque weighing device, coupled with a transducer that outputs a measurement signal representing the weight of the receptacle. An alert or alarm may be generated by a signaling device in response to the measurement signal.

Abstract: A system for providing communications for container security is provided. The system includes a sensing system for monitoring the contents of the container; a signal receiving element for receiving sensor data from the sensing system; a control element for analyzing received sensor data; a first transceiver element for receiving signals containing sensor data from within the container and for transmitting those signals outside of the container; and a satellite transceiver element for receiving signals from the first transceiver element and for forwarding the received signals via satellite uplink to a remote location.

Abstract: A filling degree gauge for measuring and displaying a residual filling potential of a target area, such as a container, being filled through a target, such as an open top, with goods by a goods carrier, such as a discharge spout, of an agricultural vehicle, such as a harvester, has a 3D sensor for observing at least a part of the target area including at least a part of the target, a data control system and a visual display unit. The data control system operates to provide on the visual display unit a visual display indicating residual filling potential by indicating the current one of at least three different levels of residual filling potential.

Abstract: An exemplary embodiment of a system includes first and second sensors. The first sensor is operable to provide an output indicative of a sensed refrigerant liquid temperature of a liquid refrigerant line that is within or extending from an outlet of a condenser coil of an air conditioner or heat pump unit. The second sensor is operable to provide an output indicative of a sensed refrigerant liquid pressure in the liquid refrigerant line. A controller is configured to determine at least one target pressure value from the output indicative of the sensed refrigerant liquid temperature of the liquid refrigerant line. The controller is configured to determine if the level of refrigerant charge is at, above, or below an acceptable level based on a comparison of the output indicative of sensed refrigerant liquid pressure to the at least one target pressure value.

Abstract: A contact is provided for a fluid level detection apparatus. The contact includes a contact support spring for rotating in response to a change in fluid level. The contact support spring includes a cantilevered spring arm having a proximal end to be fixed to a holder and a free end, and a contact support which is provided at the free end. First and second contacts are attached to the contact support in first and second positions, respectively, the first position being set at one end opposite to an end at which the second position is set. The joining position of the contact support and cantilevered spring arm is set so that a pressing load applied to the first and second contacts on the contact support by the flexure displacement of the contact support spring falls within a predetermined range.

Abstract: A refrigerator may include a main body having a storage chamber formed therein, a cooling device for cooling the storage chamber, and a door for opening and closing the storage chamber. A basket may be installed at the door and a pressure sensor may be provided on the basket to detect a pressure applied by a storage item stored in the basket. A controller may output a control signal based on the pressure detected by the pressure sensor to a display that displays a residual amount of the item stored in the refrigerator.

Abstract: A system for monitoring the fermentation process in connection with ensilage of fodder (1) comprises a sensor device (3) arranged in the fodder during the ensilage thereof and a monitoring device (11) operatively connected to the sensor device during the ensilage. The sensor device (3) comprises at least one sensor (3a-c) provided for repeatedly measuring the content of at least one chemical substance in the fodder, which is affected by the fermentation process. The monitoring device comprises receiving means (12) provided for receiving the repeatedly measured values of the content of the chemical substance; processing means (13) provided for comparing the repeatedly measured values with reference values of the content of the chemical substance; and notifying means (14-16) provided for notifying a farmer (17) depending on the outcome of the comparison of the repeatedly measured values and the reference values.

Abstract: Various methods and systems are provided for monitoring fuel usage and/or remaining run time of backup power sources. In one embodiment, a method includes tracking run time of a backup power source; determining a current fuel level associated with the backup power source; and providing a fuel level warning. In another embodiment, a system includes a fuel monitoring system including logic that obtains a current run time corresponding to a backup power source; logic that determines a current fuel level based at least in part upon the current run time, the current fuel level corresponding to a fuel source supplying the backup power source; and logic that provides a fuel level warning based upon the current fuel level and a predefined fuel level threshold.

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: A method for warning of a residual amount of liquid detergent includes: calculating a total use amount of liquid detergent by adding up a use amount of liquid detergent whenever a washing process is performed; and comparing the total use amount of liquid detergent to a reference amount, and warning of a residual amount of liquid detergent according to the comparison result. Accordingly, a user does not need to frequently check the residual amount of liquid detergent, and may easily fill up a container with the liquid detergent. Furthermore, since a sensor for sensing the residual amount of liquid detergent is not installed, it is possible to reduce the manufacturing cost of the washing machine and to prevent a user from getting an electric shock from a current leaking to the container.