Abstract: A system for separating a sample and collecting the separated sample. The system includes an ultracentrifuge having a cylindrical rotor. The system includes a gradient delivery assembly for delivering a gradient solution to the ultracentrifuge rotor, and a sample delivery assembly for delivering the solution containing the sample to the ultracentrifuge rotor. The system includes a fraction collection assembly for collecting discrete volumes of the separated sample. The system includes a processor for controlling operation of the ultracentrifuge, as well as the gradient delivery assembly, the sample delivery assembly, and/or the fraction collection assembly.

Abstract: The present invention discloses a laser liquid level detection device with linear optical magnification of a curved minor, wherein two openings are disposed at a top of a single crystal furnace symmetrically, a laser device and a CCD detecting device are respectively disposed on the two openings, and signal processing devices are pre-disposed within the laser device and the CCD detecting device. In the liquid surface height detection method using the device of the present invention, a model is first established to simulate the laser propagating path, a polynomial curve function of the curved mirror satisfying the requirement is calculated, the prepared curved minor is then disposed in the CCD detecting device, the change in the height of the liquid surface of molten silicon may be reflected on a CCD sensor, and therefore the actual change in the height of the liquid surface of molten silicon may be calculated.

Abstract: A liquid level sensor probe for determining liquid level within a vessel, the liquid level sensor probe comprising at least one light source positioned for emitting radiant energy; at least one photosensor positioned for detecting an amount of radiant energy received from at least one light source wherein a change in the amount of radiant energy as detected by at least one photosensor is indicative of a change in liquid level within the vessel; at least one light shield positioned between at least one light source and at least one photosensor wherein at least one light shield prevents radiant energy from directly hitting at least one photosensor; and encapsulation material.

Abstract: A fluid flow control system using flow rate changes to extract additional information from an in-line flow sensor. The system provides the ability to determine a position of a movable flow sensor element of a flow sensor by illuminating a photosensitive pixel array with a light source to create a first set of pixel intensity values introducing an abrupt change to the fluid driving pressure, illuminating the photosensitive pixel array with a light source to create a second set of pixel intensity values, and calculating the difference between the first and second sets of pixel intensity values as a function of pixel position.

Abstract: The invention relates to a device and a method for the continuous optical determination of the fill level of liquids in a liquid tank of a vehicle or airplane which have a refractive index of at least 1.33 at room temperature and at a wavelength of 589 nm. The device has an elongate measurement channel (3) which can be arranged on or in a liquid tank. A light emitting means (8, 8?) is arranged such that light (13, 14) emitted by the light emitting means (8, 8?) is introduced into the measurement channel (3). A detector arrangement (12, 8?) is arranged such that light (10) emitted into the measurement channel (3) by the light emitting means (8, 8?) is incident on the detector arrangement (12, 8?). The wall (15) which defines the measurement channel (3) is designed such that the reflection coefficient for light of the predetermined wavelength or from the predetermined wavelength range is at least 70%, at least for an angle of incidence up to a predetermined limit angle.

Abstract: An automated medication preparation system for preparing a prescribed dosage of medication in a drug delivery device. The system includes a plurality of stations for receiving, handling and processing the drug delivery device so that the prescribed dosage of medication is delivered to the drug delivery device and a transporting device that receives and holds more than one drug delivery device and moves the drug delivery devices in a controlled manner from one station to another station. The system is configured so that two or more separate drug delivery devices can be acted upon at the same time.

Abstract: A system and method for identifying the levels of one or more liquids in a vessel using an optical imager and one or more appropriately positioned light sources and an optical imager for capturing digital images of the illuminated vessel. A laser line generator is positioned oppositely from the imager and oriented to project a laser line through the vessel so that it may be imaged by the imager. A second light source, such as an LED, may be positioned above or below the vessel and oriented to project light downwardly or upwardly through the vessel and its contents. Captured images of the vessel are then processed by a programmable device, such as a microcontroller, to determine the levels of materials in the vessel based on the optical characteristics revealed in the captured image.

Abstract: Embodiments of the present invention provide a system and method for detecting the level of a fluid in a surgical cassette by projecting light from a linear light source into a wall of a cassette. Depending on the amount a light reflected or refracted in the cassette (i.e., due to the cassette material/fluid interface or cassette material/air interface (or other interface)) various portions of a linear sensor array will be more or less illuminated. By examining the illumination of the linear sensor array, the level of fluid in the chamber can be determined.

Abstract: An apparatus for monitoring a position of a semiconductor process fluid interface in a dispense nozzle includes an extended optical source adapted to provide an optical beam propagating along an optical path. The optical beam is characterized by a path width measured in a first direction aligned with a dispense direction. The apparatus also includes an optical detector coupled to the optical path and adapted to detect at least a portion of the optical beam and a dispense nozzle disposed along the optical path at a location between the extended optical source and the optical detector. The apparatus further includes a nozzle positioning member coupled to the dispense nozzle and adapted to translate the dispense nozzle in the first direction.

Abstract: Optical sensor system on a device for the treatment of liquids with at least one device for the projecting of light in the direction of an optical axis onto at least one illumination area in the space, an adjustment device for the adjustment of the relative position of the at least one illumination area and a boundary surface in a direction diagonal to the optical axis, an adjustment device for the adjustment of the relative position of the at least one illumination area and the boundary surface in the direction of the optical axis, a control device for controlling the adjustment devices, such that they simultaneously adjust the relative position of the at least one illumination area and the boundary surface diagonal to the at least one device for the imaging of the at least one illumination area during the adjustment of the relative position onto at least one photodetector and an evaluation device connected with the at least one photodetector for the evaluation of the at least one measurement signal.

Abstract: An apparatus for monitoring the consumption of fluid by a user, particularly fluids being drank from a container. The apparatus may be used with wide variety of container types. The fluid monitoring unit uses a pair of gears in rotational engagement with each other such that fluid passes around them and rotation of at least one gear is indicative of fluid consumption. The gears in at least one exemplary embodiment are arranged to have low frictional resistance with respect to each other and their respective axles such that the gears quickly and easily rotate and over a wide fluid flow range. This allows the apparatus to accurately and consistently monitor fluid flow from very low flow rates to high flow rates and therefore provide very reliable consumption information. The apparatus in one exemplary embodiment includes an electromagnetic drinking straw embodiment that allows a user to monitor the consumption of fluids from virtually any container type.

Abstract: A fluid flow control system using flow rates to extract additional information from an in-line flow sensor. The system provides the ability to determine a position of a movable flow sensor element of a flow sensor by illuminating a photosensitive pixel array with a light source to create a first set of pixel intensity values introducing an abrupt change to the fluid driving pressure, illuminating the photosensitive pixel array with a light source to create a second set of pixel intensity values, and calculating the difference between the first and second sets of pixel intensity values as a function of pixel position.

Abstract: A fluid overfill probe is resistant to failure caused by physical stresses resulting from thermal expansion of probe components. A fluid level detector is connected to circuit components that are mounted on a circuit board located in a housing of the probe. The circuit board is located within a tube that is positioned within, and secured to the housing, and the circuit board is secured to an inner surface of the tube along its edges. The tube has a shape and rigidity sufficient to maintain a gap between the circuit components and the inner surface of the tube such that thermal expansion of probe components result in no physical stress to the circuit components.

Abstract: The present invention relates to a component for a household appliance, in particular for a dishwasher, and to a sump for a household appliance, in particular for a dishwasher, using it. Both the component and the sump are adapted to detect and/or control the level of a liquid in a tub. The component and/or the sump comprise a light transmitter adapted to generate a light beam, a light receiver adapted to receive the said light beam, and at least one optical element, in particular made of transparent material, adapted to affect the said beam depending on the content of the tub.

Abstract: A level detection device for detecting an upper surface of a liquid at a reference level. The device includes a reservoir having a bottom wall and one or more side walls that delimit a cavity for containing the liquid; a light emitter for emitting a light beam towards this cavity; at least one reflection surface for reflecting the light beam; and a light detector for detecting the emitted light beam upon reflection. The emitter and detector are so arranged that, when the surface of the liquid passes the reference level, a state of detection of the light beam by the detector is changed. The emitter, detector and reflection surface(s) are so located and oriented relative to the cavity that the emitted light beam is: detectable by the detector upon travelling through the liquid in the cavity; and refractable at the surface of the liquid towards or away from the detector so that the state of detection is a function of such refraction.

Abstract: Embodiments of the present invention provide a system and method for detecting the level of a fluid in a surgical cassette by projecting light from a linear light source into a wall of a cassette. Depending on the amount a light reflected or refracted in the cassette (i.e., due to the cassette material/fluid interface or cassette material/air interface (or other interface)) various portions of a linear sensor array will be more or less illuminated. By examining the illumination of the linear sensor array, the level of fluid in the chamber can be determined.

Abstract: The inventive optical sensor consists of an LED semiconductor material and elements (herein after the LED components) surrounded by a transparent encapsulant that allows much of the light produced by the LED components to pass while a certain small percentage of the light is internally reflected. The percentage of light internally reflected, depends upon whether at least a front face of the encapsulant is immersed in liquid or in air. The optical liquid sensor also consists of a strategically placed photo sensor that detects the intensity of light that is internally reflected by at least the front face of the encapsulant surrounding the LED. The photo sensor is able to detect the change in intensity of light being internally reflected by at least the front face of the encapsulated LED when the front face, for example, emerges from immersion in a liquid.

Abstract: An optical switch having a housing, a light source and a light detector. The light source and light detector are located remote from the housing, The light source is connected to the housing with a first light guide, and the light detector is connected to the housing with a second light guide. The first and second light guide cables have distal ends positioned through the housing and are optically aligned but separated by a gap. The switch includes a device to interrupt a light beam that is usually adapted to removably occupy the gap.

Abstract: Embodiments of the present invention provide a system and method for detecting the level of a fluid in a surgical cassette by projecting light from a linear light source into a wall of a cassette. Depending on the amount a light reflected or refracted in the cassette (i.e., due to the cassette material/fluid interface or cassette material/air interface (or other interface)) various portions of a linear sensor array will be more or less illuminated. By examining the illumination of the linear sensor array, the level of fluid in the chamber can be determined.

Abstract: The present invention provides a method of operating an infrared drip sensor in an enteral pump system to reduce false alarm conditions. The method consists of the following steps: optically coupling a infrared beam emitter with an infrared beam detector along an infrared beam path that extends through a drip chamber and intersects the drip path; monitoring the output signal of the infrared beam detector to detect pulses; monitoring the pulses for an interruption thereof; and running an infrared beam power update routine when an interruption is detected in the pulses, the infrared beam power update routine consisting of incrementally increasing a power level of the infrared beam until the power level of the infrared beam is sufficient to re-establish an output signal at the infrared beam detector.

Abstract: Methods and systems are provided for monitoring a solid-liquid interface, including providing a vessel configured to contain an at least partially melted material; detecting radiation reflected from a surface of a liquid portion of the at least partially melted material that is parallel with the liquid surface; measuring a disturbance on the surface; calculating at least one frequency associated with the disturbance; and determining a thickness of the liquid portion based on the at least one frequency, wherein the thickness is calculated based on L = f 2 ? w 2 g , where g is the gravitational constant, w is the horizontal width of the liquid, and f is the at least one frequency.

Abstract: The present invention discloses a device and an optical liquid sensor for drug screening, and a method for using these. More particularly a device, an optical liquid sensor, and a method, for repeatable measurements of the effect of a test drug on a biological tissue sample are described.

Abstract: Methods and systems are provided for determining the density and/or temperature of a fluid based on the manner in which optical energy is affected as the optical energy propagates across a gap between opposing end faces of optical waveguides, or the manner in which the optical energy is reflected from interfaces of optical waveguides and the fluid.

Abstract: A fluid overfill probe is resistant to failure caused by physical stresses resulting from thermal expansion of probe components. A fluid level detector is connected to circuit components that are mounted on a circuit board located in a housing of the probe. The circuit board is located within a tube that is positioned within, and secured to the housing, and the circuit board is secured to an inner surface of the tube along its edges. The tube has a shape and rigidity sufficient to maintain a gap between the circuit components and the inner surface of the tube such that thermal expansion of probe components result in no physical stress to the circuit components.

Abstract: A system and method of determining fluid levels in containers is disclosed. In a particular embodiment, a first value of infrared energy associated with an empty portion of a container is detected and the container is scanned to detect a second value of infrared energy that is different from the first value of infrared energy. The method also includes to store an upper limit value associated with a vertical location of an upper surface of a fluid level when the second value of infrared energy is detected and to scan the container to detect a third value of infrared energy that is different from the second value of infrared energy. In addition, a lower limit value associated with a vertical location of a lower surface of the fluid relative to the upper surface is stored when the third value of infrared energy is detected. A height of the fluid is determined using a difference between the upper limit value and the lower limit value.

Abstract: A system and method of determining fluid levels in containers is disclosed. In a particular embodiment, a first value of infrared energy associated with an empty portion of a container is detected and the container is scanned to detect a second value of infrared energy that is different from the first value of infrared energy. The method also includes to store an upper limit value associated with a vertical location of an upper surface of a fluid level when the second value of infrared energy is detected and to scan the container to detect a third value of infrared energy that is different from the second value of infrared energy. In addition, a lower limit value associated with a vertical location of a lower surface of the fluid relative to the upper surface is stored when the third value of infrared energy is detected. A height of the fluid is determined using a difference between the upper limit value and the lower limit value.

Abstract: A method and apparatus provide for non-contact optical measurement of the level of a fluid stored in a tank or container, the surface of the fluid being possibly agitated. The method processes numerically the digitized signal waveforms generated by a lidar apparatus based on a pulsed time-of-flight modulation scheme. A key step of the numerical processing is the computation of a waveform in which each data point is obtained from a statistical estimator of the variability of the amplitude signal echo measured at the distance from the lidar apparatus that corresponds to the rank of the data point in the waveform. The statistical estimator is preferably the standard deviation. By using a statistical estimator of the variability of the captured signal amplitude, the specific signal echo returned from an agitated fluid surface can be greatly amplified as compared to the signal echoes returned from any obstacle or medium that could be present along the path of the optical beam radiated by the lidar apparatus.

Abstract: A method and apparatus provide for non-contact optical measurement of the level of a fluid stored in a tank or container, the surface of the fluid being possibly agitated. The method processes numerically the digitized signal waveforms generated by a lidar apparatus based on a pulsed time-of-flight modulation scheme. A key step of the numerical processing is the computation of a waveform in which each data point is obtained from a statistical estimator of the variability of the amplitude signal echo measured at the distance from the lidar apparatus that corresponds to the rank of the data point in the waveform. The statistical estimator is preferably the standard deviation. By using a statistical estimator of the variability of the captured signal amplitude, the specific signal echo returned from an agitated fluid surface can be greatly amplified as compared to the signal echoes returned from any obstacle or medium that could be present along the path of the optical beam radiated by the lidar apparatus.

Abstract: Disclosed are scanning devices which measure and quantify optical properties within an object such as the absorption of light, refractive index, light scattering, fluorescence, and phosphorescence. Through the use of two rotating plane mirrors and two paraboloid mirrors, a laser light beam is made to traverse the object to be scanned wherein the beam is always parallel to the optical axis. The invention provides an improvement over previously reported scanning devices by virtue of increased speed and resolution. Two-dimensional projections gleaned by each scan of the object are reconstructed into a three-dimensional image through the use of various computer techniques.

Abstract: A tilt detector and tilt detecting method for the same are disclosed. The tilt detector includes a light-detecting unit and a light-permeable unit. The light-detecting unit includes a body, a window formed on the body, and a signal port device formed on the body. The window detects the position of a moving facula, and the signal port device outputs the facula location signal. The light-permeable unit mounted in the window and includes a chamber, an opaque fluid filled with the chamber, and a light-permeable substance formed on the opaque fluid. The window detects a facula by the light-detecting unit when a beam is emitted to the window via the light-permeable substance. Therefore, the level of a subject is detected by observing the light-permeable substance directly, and obtains the precise level by the signal outputted from the signal port device.

Abstract: A system for detecting a container or contents of the container. The system includes a diffuser for retaining the container, where the container is configured to hold an active material therein and may include a wick extending therefrom. The system further includes a sensor positioned to detect, for example, the container retained in the diffuser and/or the contents of the container retained in the diffuser.

Abstract: There is disclosed a fiber optic liquid level sensor apparatus that functions using total internal reflection and an index of refraction. More specifically, there is disclosed a fiber optic liquid level sensor apparatus comprising two fiber optic strands, each having a first end and a second end, substantially oriented in parallel to each other, wherein the second ends of both strands are attached to each other.

Abstract: A body fluid sampling device (100) includes: a connecting portion (105) to which a body fluid container is connected; a suctioning portion (117) which suctions a gas in the body fluid container connected to the connecting portion, to introduce a body fluid into the body fluid container; a suctioning passage (105a) which causes an inside of the suctioning portion and an inside of the body fluid container connected to the connecting portion, to be communicated with each other; a first electrode (112) which is disposed to extend across the suctioning passage and has gas permeability; a second electrode (113) which is disposed to extend across the suctioning passage and be opposed to the first electrode, and has gas permeability; and a detector which detects an electric signal generated between the first electrode and the second electrode.

Abstract: The invention relates to a method for monitoring the filling of a capsule with a medicament, a corresponding filing method and the corresponding devices. According to the monitoring method, after at least part of the capsule is filled with a given filling mass of given closed shape of medicament, in a first step, at least the filling mass located in the part of the capsule after filling is recorded with a digital image, in a second step, the shape of the filling mass located in the part of the capsule is determined from the digital image and, in a third step, the shape analysed to give an analysis of the filling in comparison with given shapes.

Abstract: In an automatic analyzer which includes a reaction container which contains reaction solution therein, a light source which emit light to be transmitted through the reaction solution, a spectral detector which measures the light transmitted through the reaction solution, a memory which stores light measurement data measured by the spectral detector and a CPU which calculates the light measurement data stored in the memory to obtain a light intensity, wherein the spectral detector measures the light over an entirety of an area from one end to the other end of the reaction container at a portion where the reaction solution reserves, the memory stores the light measurement data measured by the spectral detector, and light measurement data in an area where the reaction solution exists is obtained from the memory to calculate a light intensity.

Abstract: The present subject matter relates to the continuous optical determination of the fill level of liquids in a liquid tank of a vehicle or airplane which have a refractive index of at least 1.33 at room temperature and at a wavelength of 589 nm. A device embodiment has an elongate measurement channel in which the liquid in the tank can enter the channel and form a liquid column. A light emitting means is arranged to introduce light into the channel and pass at least partly through the liquid column Light emitted into the channel is incident on a detector arrangement after passing through at least a part of the liquid column. The wall defining the channel is designed to provide a reflection coefficient of at least 70% at the wall in the region of the liquid column at least for an angle of incidence up to a predetermined limit angle.

Abstract: Broadly speaking the present invention is directed to a system for calculating a volume of fluid that is disposed within a container. The system includes (1) an imaging device that captures and stores an image of at least the volume of fluid in the container; (2) a background disposed behind the container so that at least the volume of fluid in the container is disposed in front of the background; and (3) a processor that performs at least one operation on the stored image to calculate the volume of the fluid within the container.

Abstract: To provide a lubricant deterioration detecting device having a high degree of freedom in arranging within the bearing assembly or the like and capable of stably detecting the status of deterioration of the lubricant without being affected by the thickness of the lubricant and a change in temperature and also to provide a detector incorporated bearing assembly equipped with such lubricant deterioration detecting device, the lubricant deterioration detecting device includes a light source, a plurality of light detecting components for detecting rays of light emitted from the light source and subsequently transmitted through a lubricant, and a determining unit. The plural light detecting components have respective light detecting faces sequentially displaced in position. The determining unit compares respective signal strengths of outputs from the plural light detecting components to detect the status of deterioration of the lubricant.

Abstract: A multi-pass gas cell that operates with reflected radiation pass through a gas, the reflected radiation transmitted and received by first and second fiber optic ports that are subject to an alignment adjustment, and a mirrored viewing window having a inner reflective surface exposed to an interior of the elongated cell body for reflecting the radiation within the cell body, an outer viewing surface, and a transmittance characteristic that permits a portion of the radiation to pass through the mirrored window, from the inner reflective surface to the outer viewing surface, as a visual indicator of the alignment condition of the reflected radiation relative to the first and second fiber-optic ports.

Abstract: A detection system for determining material level in a container where the container has an opening and an optical window mounted to the opening. A sensor element is mounted to the container adjacent the window. The sensor element has an optical emitter and an optical receiver positioned to form a triangular vertex with the material surface level within the container.

Abstract: The invention provides an optical liquid level sensor used to determine the level of a liquid within a vessel. The sensor includes two adjacent elongated optical elements, such as optical fibers, which connect a first end, or “sensing end”, to a second end, or “non-sensing end”. The sensing end includes an optical lens for sensing the level of a high temperature liquid, while the non-sensing end includes electronic components for processing optical signal data relating to the sensed liquid level. The ends are sufficiently separated by the elongated optical elements, such that high temperatures exerted on the sensing end when it is immersed in high-temperature liquid are not exerted on the non-sensing end. This configuration avoids the temperature degradation of the electronic components, thus extending the lifetime of the sensor.

Abstract: Embodiments of the present invention provide a system and method for detecting the level of a fluid in a surgical cassette by projecting light from a linear light source into a wall of a cassette. Depending on the amount a light reflected or refracted in the cassette (i.e., due to the cassette material/fluid interface or cassette material/air interface (or other interface)) various portions of a linear sensor array will be more or less illuminated. By examining the illumination of the linear sensor array, the level of fluid in the chamber can be determined.

Abstract: The present application relates to an apparatus and method for measuring liquid levels in small-volume wells.

Abstract: A detection system for determining material level in a container where the container has an opening and an optical window mounted to the opening. A sensor element is mounted to the container adjacent the window. The sensor element has an optical emitter and an optical receiver positioned to form a triangular vertex with the material surface level within the container.

Abstract: A system for determining the amount of LC that is dropped on a display panel is presented. The system can adjust the amount of the LC to be dropped based on a real-time feedback on the amount of LC that is currently being dropped. The amount of LC that is being dropped is detected by utilizing a light source and a CCD camera. Because LC is not consumed wastefully and the detection interval is shortened with this system, the amount of LC that is dropped can be controlled more accurately and manufacturing cost is reduced.

Abstract: A sensing system (22) for a device (34) contains a light absorbing or scattering object (44). An illumination device (50,72) generating and emitting an illumination beam into the object (44). A first light filter (85) has at least one associated light spectrum filtering frequency. A first light sensor (60,80) is coupled to the first light filter (85), receives a first object-emitted portion of the illumination beam, and generates a first signal in response to the first portion. A second light filter (88) has at least one associated light spectrum filtering frequency. A second light sensor (62,82) is coupled to the second light filter (88), receives a second objected-emitted portion of the illumination beam, and generates a second signal in response to the second portion. A controller (54) generates a parameter signal, associated with a characteristic of the object, in response to the first signal and the second signal.

Abstract: A system enables indirect determination of a position vector (VR) of a point position (P). The system uses two fixed trackers (10 and 10?) whose absolute positions are known. A movable measuring device (20) provides a rigid rod (25) supporting a pair of reflectors (30 and 30?) which are mounted at fixed positions. A reference point (R) is mounted at a further fixed position on the rod (25) and is on a straight line (L) through the reflectors (30 and 30?). Light beams from the trackers (10 and 10?) acquire the reflectors (30 and 30?) so that when the reference point (R) is positioned at the point position (P), the position vector (VR) of point position (P) is determinate by vector addition.

Abstract: Systems and methods for fluid level detection are disclosed. In one embodiment, a sensor assembly includes at least one optical fiber adapted to at least one of transmit and receive an optical signal, and a moveable float member. The float member is adapted to move in a first direction as the fluid level increases and in a second direction as the fluid level decreases. The float member blocks the optical signal at a first value of the fluid level, and allows the optical signal to pass at a second value of the fluid level. The presence or absence of the optical signal is detected to determine the level of fluid.

Abstract: An optical transducer for determining the presence or absence of liquid or the like in a reservoir includes a housing with a hollow interior and an optical probe that extends through the housing. The optical probe has a central axis, a proximal end positioned in the hollow interior and a distal end positioned outside of the housing. The distal end has first and second measurement surfaces that intersect at a transverse edge. The transverse edge extends at an acute angle with respect to the central axis. A light source is arranged for projecting radiant energy into the optical probe toward the distal end. A photosensor is arranged for detecting radiant energy reflected from the distal end to thereby detect the presence and absence of liquid on the optical probe.

Abstract: An optical transducer for determining liquid level within a container includes a sensing probe having a first elongate measurement face and a second elongate measurement face that converges toward the first measurement face. A light source is positioned for directing radiant energy into the sensing probe and a photosensor is positioned for detecting an amount of radiant energy exiting the sensing probe. With this arrangement, a change in the amount of radiant energy as detected by the photosensor is indicative of a change in liquid level within the container.