Abstract: An apparatus for determining a value that represents an amount of liquid in a vessel, wherein the vessel is configured to be a tube or a cuvette. The vessel for the liquid is basically transparent, with at least one radiation unit, that is arranged alongside the longitudinal axis of the vessel and that radiates light into the vessel, as well as at least one light detector with at least one light receiver that is assigned to the radiation unit and that receives the light that is coming through the vessel and forwards it to the light detector. The apparatus comprises a data processing unit that determines the value that represents the amount of the liquid in the vessel from the light that was detected by the light detector. The apparatus is characterized in that the light detector detects the sum total of the light that was radiated through the vessel and was received by all light receivers. Furthermore, the invention relates to the use of the apparatus in an analyzer.

Abstract: A device for evaluating the foaming property of a gas-soluble surfactant, which comprises a gas source part, an evaluating kettle, a liquid part, and an intermediate container part. The rotation of the evaluating kettle, the gas-soluble surfactant and the supercritical carbon dioxide can be sufficiently and evenly mixed with each other when the solubility of the gas-soluble surfactant in the supercritical carbon dioxide is measured.

Abstract: A body fluid test system includes a test chip, an image capturing device, a moving mechanism for test tube and at least one fluid transfer device. The image capturing device is for capturing image of the test chip. The moving mechanism includes a base and a test tube carrier. The test tube carrier is movably disposed on the base. The test tube carrier is for carrying at least one test tube. One end of the fluid transfer device corresponds to the top of the test tube carrier, and another end of the fluid transfer device corresponds to the test chip. The test tube carrier is movable upwardly from a pre-testing position to a testing position. When the test tube carrier is at the testing position, the fluid transfer device is for transferring a body fluid sample contained in the at least one test tube to the test chip.

Abstract: The circuit of the present invention comprises a detection module and a feedback module, wherein an output end of a power supply management module is coupled to one end of a voltage level shift module, and the other end of the voltage level shift module is coupled to a first end of the detection module, and a second end of the detection module is coupled to a WOA route module or a GOA route module, and a third end of the detection is coupled to one end of the feedback module, and the other end of the feedback module is coupled to an enable end of the power supply management module, and the detection module detects whether the WOA route module or the GOA route module is short, and feeds back a short signal; the feedback module receives the short signal, and sends a disable signal to the enable end.

Abstract: An implantable device for measuring biological information of a body is provided, wherein the implantable device includes a receiver for receiving electromagnetic energy and converting the electromagnetic energy into electrical energy; a storage capacitor associated with the receiver such that the electrical energy from the receiver is stored in the storage capacitor; a biological sensor; a processing device; and a transmitter, wherein the biological sensor, processing device and transmitter are configured to receive electrical energy from the storage capacitor, and wherein the biological sensor, processing device and transmitter are configured such that when the receiver is receiving electromagnetic energy, the biological sensor, processing device and transmitter are inactive and when the receiver is not receiving electromagnetic energy, the biological sensor, processing device and transmitter are inactive.

Abstract: A sensor for measuring a level of a liquid such as fuel and/or water in a tank such as a fuel tank. The sensor includes a stack of capacitors, each capacitor with one or more graphene measurement electrodes and one or more graphene reference electrodes. A measurement system is arranged to measure a capacitance of each capacitor between its measurement electrode(s) and its reference electrode(s) and thereby infer the liquid level. The graphene measurement and reference electrodes are formed in a single layer of graphene oxide by reductive etching.

Abstract: A measuring device (10) and a measurement method measure a concentration of gaseous/aerosol components of a gas mixture. A reaction carrier (14) has a flow channel (42) defining a reaction chamber (46) having a optically detectable reaction material (48), that reacts with a gas mixture component or with a reaction product. The measuring device (12) includes a gas-conveying assembly (2) with a gas-conveying apparatus (28) conveying the gas mixture and a detection assembly (3), which has a lighting apparatus (37) for lighting the reaction chamber (46), an optical sensor (38) for sensing the optically detectable reaction, and an evaluating unit (4) evaluating sensor data and determining a concentration of the component of the gas mixture. The detection assembly (3) senses a speed of a reaction front (6) propagating in the flow direction in the reaction chamber (46) and determines a preliminary concentration from the speed of the reaction front (6).

Abstract: An optical spectral sensing device for determining at least one property of a fluid. The device has an elongated porous body, a first end and a second end, a solid-state optical emitter at the first end of the body oriented to emit radiation toward the second end of the body, and a solid-state optical detector at the second end of the body oriented to detect radiation emitted by the optical emitter and to output a signal responsive to absorption of radiation. The device is configured to determine depth of a fluid based on the signal output by the optical detector.

Abstract: A new multiparameter device for measuring by optical means, the level of filling of tanks and reservoirs for liquids and liquefied products, index of refraction and image analysis, without moving parts, which is more specifically intended, but without restrictions of application, for the measuring the level of a liquid in a reservoir, besides being able to make possible the distinction and detection of the type of liquid included in this reservoir, by measuring the index of refraction and image analysis of these liquids, performing this task in a simple, practical and efficient manner through a specific configuration utilizing optical and electronic means, without use of moving parts, what allows that the same may be used for numerous applications between them, for the fuel quality control, the fuel identification, the measuring of the index of refraction, flow measurement, color measurement, temperature measurement and pressure measurement, inter alia, and more specifically for application in the automotive

Abstract: A system and a process for detecting oil quality includes a light source configured to generate light within an oil container and a sensor configured to detect light from the light source after it has traversed through the oil in the oil container and generate an output signal. The system and process further includes a monitor configured to receive the output signal from the sensor and determine an oil quality of an oil in the oil container.

Abstract: A developer detector includes a sensor housing portion, an optical sensor, and a cleaning portion. The sensor housing portion can be installed on a wall surface of a hopper storing a developer. The sensor housing portion includes a detection surface, and a step surface protruding a smaller amount from the wall surface than the detection surface to form a step height from the detection surface. The optical sensor is housed in the sensor housing portion and detects the developer through the detection surface. The cleaning portion moves in a moving region including a first region facing the detection surface and a second region facing the step surface and cleans the detection surface on the way of moving. The cleaning portion includes a flexible member and makes the flexible member slide on the detection surface while making the flexible member contact the detection surface under pressure in the first region.

Abstract: An ink tank 25A includes an ink containing portion 120, an ink injection portion 113, an ink supply portion 117, and a pair of electrode pins 140a and 140b. The ink containing portion 120 has a visual check portion 114 that enables the position of the liquid surface of ink contained in the ink containing portion 120 to be visually checked from the outside in a reference posture, which is a posture at the time when the ink is supplied from the ink tank 25 to the print head portion 32. The ink supply portion 117 is connected to a lower portion 122A located below a lower end of the visual check portion 114 in the reference posture. Leading end portions 143a and 143b of the electrode pins 140a and 140b are arranged in the lower portion 122A.

Abstract: A method includes obtaining a substrate having at least one exposed metal surface. The method also includes electro-depositing metal onto the at least one exposed metal surface of the substrate and around at least a portion of an optical fiber to secure the optical fiber to the substrate. The substrate and the electro-deposited metal are configured to remove heat from the optical fiber. The method could further include electro-depositing metal around a sacrificial material and removing the sacrificial material to form at least one cooling channel through the electro-deposited metal. The optical fiber could include a polymer coating, where a portion of the polymer coating is removed at an end of the optical fiber. The substrate and the electro-deposited metal could be faceted at an input of the optical fiber and at an output of the optical fiber. The optical fiber could have a coiled arrangement on the substrate.

Abstract: A device for detecting the concentration of a given component in a solution, preferably the concentration of urea in solution with water includes a means for emitting radiation, at least one means for receiving radiation, which is prearranged for determining at least one characteristic of the radiation, and a light guide, which is prearranged for optically connecting the emitting means to the receiving means, wherein the light guide has at least one surface that is to come into contact with the solution so as to determine an interface of separation between the propagation medium and the solution. Control means are configured for obtaining a value indicating the concentration of the compound in the solution as a function of the signal coming from the receiving means.

Abstract: An optical sensor enables a level of reflective fluid to be detected. The optical sensor includes a prism mounted at one end of a housing. The prism has an exterior surface that is parallel to the end of the housing and a width that corresponds to a width of the end of the housing. A photoemitter and a photodetector are mounted at another end of the housing to enable light emitted by the photoemitter to be reflected by the prism when the prism contacts reflective fluid and to enable light emitted by the photoemitter to pass out of the sensor when the prism is in contact with air.

Abstract: An oil detection device for a compressor to detect at least two levels of oil in the compressor includes a first detection unit including a first reference electrode and a first detection electrode disposed at both sides of the first reference electrode, and a second detection unit including a second reference electrode spaced from the first reference electrode and a second detection electrode disposed at both sides of the second reference electrode.

Abstract: Use of improved image acquisition for a medical dose preparation system. The medical dose preparation system may include a work station for capturing medical dose preparation images (e.g., to document preparation of a mediation dose). The medical dose preparation image may be captured by a video data stream processor capable of performing an auto cropping technique on a video data stream received from an image device. Accordingly, memory resources may be more efficiently employed while maintaining high quality medical dose preparation images.

Abstract: A system including a container, an imaging structure, an image capturing device, and a processor. The container at least partially surrounds a liquid. The liquid has a liquid surface that is defined by a quantity of the liquid in the container, a shape of the container, and an orientation of the container relative to a horizontal plane. The imaging structure is positioned in the container. The image capturing device captures an image of the liquid surface and the imaging structure. The processor is in communication with the image capturing device for analyzing a characteristic of the image, and for determining an attribute therefrom.

Abstract: A tamper detection system for a utility meter includes an emitter configured to emit light and a detector configured to receive light. The tamper detection system also includes a light modifying feature coupled to an interior surface of a meter cover. An end portion of the light modifying feature is configured to be positioned proximate to the emitter and the detector while the meter cover is in a closed position relative to the utility meter. The light modifying feature is also configured to alter a direction of travel of the emitted light and to direct the emitted light toward the detector while the meter cover is in the closed position relative to the utility meter.

Abstract: A system and method for detecting a pathogen in a sample is provided, the system capable of measuring the volume of a sample in a container through the use of various measurement technologies, thereby ensuring that a user is aware of volumes not meeting specification and/or allowing correction of results to account for the out-of-specification sample.

Abstract: A temperature sensor is provided which comprises a measurement light source for generating measurement light and two optical waveguides. The two optical waveguides are arranged such that they respectively receive a measurement light portion of the measurement light and that the measurement light portions are superimposed after passing through the optical waveguides. Furthermore, the two optical waveguides have an optical property with different temperature dependency.

Abstract: A sensor and associated methods wherein a bolt or rod stem includes a flow path through and across the stem. A source of radiation within the stem is configured to direct radiation through the flow path and a detector subsystem in the stem is configured to detect radiation passing through the flow path. A head includes electrical conductors for the radiation source and detector subsystem resulting in a compact, inexpensive sensor.

Abstract: A monitoring and control system for a seal gas supply system for a non-contacting gas seal. The supply includes several gas conditioning elements or units. The monitoring and control system includes an evanescent wave sensor to sense the presence of liquid in the seal gas. Multiple sensors to sense the temperature and pressure of the treated seal gas are disposed at the outlet of the conditioning elements. A programmable logic device is provided with information regarding the phase of the gas at various pressures and temperatures and compares the sensed data to the baseline data. Recognition of liquid concentrate results in an output signal.

Abstract: An optical level sensor mounted to a ceiling of a tank includes a sensor tube. The sensor tube is provided with support and guidance elements extending with at least three radially distributed positions inside the tank. The support and guidance elements collect, support, and guide optical fibers to different heights of the tank. Each optical fiber has a number of input sides and a number of turns forming sensor heads between two input sides, for a different level. The corresponding support and guidance element bends the fiber in the turns forming sensor heads of a small radius r around at least one corresponding guideway.

Abstract: A photoelectric-type continuous liquid level measurement method is applied to a photoelectric-type continuous liquid level measurement device which comprises at least one sensor module formed by cascading a plurality of sensors, and comprises: driving the sensors one by one from bottom to top to take a liquid level measurement; after detecting the light intensity of a detection light returned from the position where the sensors are located, the sensors which are currently in a driving state conducting analogue-to-digital conversion on a voltage value corresponding to the detected light intensity to obtain current analogue-to-digital conversion data; according to the correlation between a preset liquid level and the analogue-to-digital conversion data, determining the liquid level of the position where the sensors are located; and summarizing to a transmitter module the liquid level measured by each of the sensors to obtain the total liquid level of a currently measured.

Abstract: A detecting apparatus for determining whether liquid crystal glasses are displaced in a cartridge is disclosed. The detecting apparatus includes: a signal sensing device for sending sensing signals to an internal of the cartridge and for receiving the reflected signals from the internal of the cartridge; a reflector installed in the internal of the cartridge for receiving the sensing signals from the signal sensing device and for reflecting the sensing signals back to the signal sensing device; and wherein a determination of whether the liquid crystal glass is displaced in the cartridge is made by determining whether the reflected signals from the reflector are received after the sensing signals are sent. Upon determining whether liquid crystal glasses are displaced in the cartridge, impurities are prevented from getting into the cartridge and thus the cleanliness is enhanced and the labor power is reduced.

Abstract: A self-alignment filling level detecting device has a reflector and a sensor detachable from each other. The sensor has a light emitter, a light sensor, and a controller. The light sensor receives different light intensities when the reflector is assembled to the sensor and when the reflector is not assembled to the sensor. Thus, the controller determines whether the reflector has been accurately engaged and aligned with the sensor or not based on sensing results of the light sensor. Since the reflector and the sensor are detachable from each other, either the reflector or the sensor can be replaced individually if any one of them malfunctions.

Abstract: Exemplary embodiments include a sphere bar probe apparatus, including a holder, a retroreflector disposed in the holder, a member having a first end and a second end, wherein the first end is attached to the holder and an end plate attached to the second end of the member.

Abstract: Its object is to allow measurement of the volume of fuel (2) using optic fiber cables (3); it is characterized in that, adhered to one or more of the inner faces of the tank (1) there is at least one sheet (4) in which a plurality of optic fiber cables (3) with different lengths are included, located between the inner face of the tank and the sheet (4). One set of the ends (10) of the optic fiber cables (3) are disposed so that they are in contact with the fuel (2) when it reaches their level, thereby allowing measurement of the fuel level at all times. The preferred embodiment distributes the optic fiber cables (3) on two opposing lateral faces of the tank (1) so that they cross over one another and in opposite directions to measure any fuel level. It is applied in aeronautics.

Abstract: The present invention provides a hollow prism for detecting liquid level in the presence of an optical beam, including a hollow member, dielectric members sealed to the hollow member with one of the dielectric members arranged at an inclined angle to the other, a sealed hollow space disposed between said dielectric members, wherein an incident optical beam enters through the first dielectric member at normal incidence and exits as an emergent beam through the second dielectric member, and wherein the emergent optical beam remains undeviated when the hollow member not immersed in a liquid medium and the emergent beam suffers deviation when immersed in the liquid medium. The present invention also provides a fiber optic liquid level detector with the hollow prism for detecting liquid levels.

Abstract: Systems and methods for determining liquid depth information in a condensate pan of a climate control unit are provided. The systems and methods radiate a light beam into a liquid contained in a condensate pan associated with a climate control unit. The light beam is detected at a point of the condensate pan that is below a surface of the liquid. Information related to the depth of the liquid is determined based at least in part on the detected light beam. The systems and methods disclosed herein can determine if liquid depth in a condensate pan is greater than a threshold depth and can control evacuation of the liquid from the condensate pan.

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 a part of the activator housing is a glowable diffuse reflector. The switch includes a moveable member that moves in a path in the switch body between an optical path present state and an optical path absent state.

Abstract: A fluid level gauge includes a housing having a first end and a second end, and a window disposed in the housing, proximate to the first end. The fluid level gauge further includes an optical sensor disposed in the housing, proximate to the second end. A prism is disposed in the housing, between the optical sensor and the window, such that the prism and the window define a fluid chamber therebetween. The housing further includes a plurality of through holes that provides a fluid path from outside the housing to the fluid chamber.

Abstract: There is provided a system for detecting distant seaborne objects by an airborne vehicle, including a seeker head having an axis in the direction of flight, a sensor mounted on the seeker's head, the sensor being operative to transmit towards the sea surface a laser radiation beam of selected wavelength and to receive from the sea water surface radiation reflected from the sea water surface and from a seaborne object, and a computing unit for differentiating between the reflection received from the sea water surface and from the seaborne object. A method for detecting distant seaborne objects by an airborne vehicle is also provided.

Abstract: A printing device has a detecting section in which a light emitting section and a light receiving section are provided, liquid reservoirs for storing liquid in which a prism is provided to reflect light emitted from the light emitting section corresponding a remaining state of the liquid, and a control section. The control section determines whether a process for air bubbles that is a process corresponding to an adhesion state of air bubbles in the prism is to be conducted or not based on a signal of light reception results obtained by receiving reflected light from the prism by the light receiving section.

Abstract: A liquid consumption device of the present invention has a holder in which an opening section is provided in a position to face a prism of an ink cartridge, a light emitting section, and a light receiving section. The holder has a region that changes a light amount of the reflected light emitted from the light emitting section and received by the light receiving section in a position spaced apart from the opening section at a predetermined distance in a main scanning direction.

Abstract: The present invention relates to a method for monitoring the filling of a capsule with a medicament, to a corresponding filling method, to the associated apparatuses, and to a computer program for controlling the method and the apparatus. In the monitoring method, after at least part of the capsule has been filled with a predefined filling mass of a predefined closed contour of the medicament, at least the filling mass in the part of the capsule after the filling operation is recorded using digital imaging in a first step, the contour of the filling mass in the part of the capsule is determined from the digital imaging recording in a second step, and the contour is analysed in a third step in order to assess the filling operation in comparison with the predefined contour. The invention provides for external influences on the image properties to be compensated for by controlling the optical system.

Abstract: This disclosure relates to a liquid dispensing apparatus for dispensing a liquid from a flexible bag. The apparatus has a support for supporting the flexible bag in use and a mounting adapted for receiving a proximal portion of the flexible bag, for progressive movement relative to the support towards an outlet located at a distal portion of the flexible bag. As the flexible bag is progressively wound up, liquid is squeezed from the proximal portion to the distal portion to dispense liquid from the outlet in a controlled manner in use. This allows desired and precise dosage portions of liquid to be squeezed from the bag and direct dosing from the flexible bag amongst other advantages.

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: The present invention relates to a beverage preparation device having a water circulation system that includes a water source with an outlet, a pump with a support member for holding and securing the pump in the device, and an integral water conduit having an inlet and outlet for guiding water from the water source to the pump. The conduit outlet is connected to the pump and the water source outlet is connected to the water conduit inlet via an annular sealing member that forms an integral protruding portion of one of the conduit inlet or the source outlet. The pump support is integral with the water conduit, in particular with the conduit outlet.

Abstract: A device for indicating the level of a liquid contained in a tank. The liquid level indication device includes: a liquid level measuring unit for measuring the level of the liquid contained in the tank; an indicating unit disposed outside of the tank to indicate the level of the liquid measured by the liquid level measuring unit; and a controller for outputting to the indicating unit a control signal based on a measurement signal obtained on measurement by the liquid level measuring unit. The indicating unit is provided with a plurality of light-emitting elements which are located respectively at positions corresponding to a plurality of positions ranging from an uppermost position to a lowermost position of the level of the liquid contained in the tank. The controller causes the light-emitting elements corresponding to the liquid level measured by the liquid level measuring unit to emit light.

Abstract: Optical sensors and sensing methods are provided. A particular method includes applying light to a first end of an optical fiber. Light reflected by at least one of a first photonic crystal sensor coupled to a second end of the optical fiber and a second photonic crystal sensor coupled to the second end of the optical fiber is detected. The first photonic crystal sensor exhibits a first reflection spectrum that changes responsive a first sensed parameter and the second photonic crystal sensor exhibits a second reflection spectrum that changes responsive a second sensed parameter. A parameter value of at least one of the first sensed parameter and the second sensed parameter is determined based on the detected light.

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: An ink cartridge for an inkjet printer is provided. The ink cartridge includes a light detection portion, a first triangular prism and a second triangular prism, made of transparent material and disposed on the light detection portion, for receiving, deflecting, or refracting light emitted by a light emitting element on the printer. Two surfaces of the second triangular prism contact ink in the ink cartridge. When the ink cartridge has ink contained therein and is installed into a printer, the light emitted by the light emitting element is totally reflected by the first triangular prism and refracted by the second triangular prism into the ink, and will not be received by a light receiving element on the printer. When the ink in the ink cartridge is exhausted, the light is totally reflected by the second triangular prism onto the first triangular prism, and then is reflected onto the light receiving element, and thus the printer detects that the ink is exhausted.

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. The switch may be embodied in a float, and includes part of the switch as a glowable member.

Abstract: An apparatus for detecting developer liquid (108) level in a plate developer section tank (104) includes a reflective surface (204) installed on at least on one edge of the developer tank; a light emitter (232) which emits light onto the reflective surface; a light detector (236) adapted to detect reflected light from the reflective surface, wherein the light emitter and the light detector are positioned relative to the reflective surface such that the emitted light from the light emitter is deflected by the developer liquid hitting the reflective surface at 90 degrees.

Abstract: Systems and methods that improve farmers' ability to measure quantities of dry agricultural materials and rates of change of those quantities are disclosed. Also disclosed are systems and methods to rapidly and effectively communicate materials quantities and rates between farm equipment operators.

Abstract: Apparatus, systems, and methods may operate to receive incident energy within a chamber defining a first part of an interaction volume that attenuates the incident energy as a function of path length to provide attenuated energy. Additional activity may include simultaneously transforming the attenuated energy characterized by a substantially exponential intensity function into resultant energy characterized by a substantially polynomial intensity function. The transformation may be accomplished using an interacted energy transformation element that defines a second part of the interaction volume, the transformation element operating to intercept the attenuated energy along a plurality of path lengths. Other activity may include transmitting the resultant energy to a receiver. Additional apparatus, systems, and methods are disclosed.

Abstract: Its object is to allow measurement of the volume of fuel (2) using optic fibre cables (3); it is characterized in that, adhered to one or more of the inner faces of the tank (1) there is at least one sheet (4) in which a plurality of optic fibre cables (3) with different lengths are included, located between the inner face of the tank and the sheet (4). One set of the ends (10) of the optic fibre cables (3) are disposed so that they are in contact with the fuel (2) when it reaches their level, thereby allowing measurement of the fuel level at all times. The preferred embodiment distributes the optic fibre cables (3) on two opposing lateral faces of the tank (1) so that they cross over one another and in opposite directions to measure any fuel level. It is applied in aeronautics.

Abstract: The present invention provides a hollow prism for detecting liquid level in the presence of an optical beam, including a hollow member, dielectric members sealed to the hollow member with one of the dielectric members arranged at an inclined angle to the other, a sealed hollow space disposed between said dielectric members, wherein an incident optical beam enters through the first dielectric member at normal incidence and exits as an emergent beam through the second dielectric member, and wherein the emergent optical beam remains undeviated when the hollow member not immersed in a liquid medium and the emergent beam suffers deviation when immersed in the liquid medium. The present invention also provides a fiber optic liquid level detector with the hollow prism for detecting liquid levels.