Abstract: An agitated flow cell had a micro/miniature vibrator device such as pager motor to agitate the flow cell and its associated sensor to bring fresh analyte to the sensor surface without the need for microfluidic channels, pumps or valves. The agitated flow cell improves the confidence measure of a given sample reading by directing the flow of sample to the sensor/sample interface in a substantially shorter period of time than that required by flow cells that rely on diffusion of analyte molecules through the liquid depletion region in order to bring the sample reliably in contact with the sensor's biosensing film.

Abstract: The invention relates to a method for detecting a low molecular weight compound in a solution which utilizes a quartz resonator and which comprises capturing a low molecular weight compound between an adsorptive film (A) for a low molecular weight compound provided on the surface of a quartz resonator and an adsorptive film (A) for a low molecular weight compound provided on the surface of a signal enhancing material and comprises detecting the shift in frequency of the quartz resonator before and after the capture.

Abstract: A method for measuring physical properties or characteristics of liquids uses an acoustic transfer system that utilizes Rayleigh waves. A wave guide with at least one test section formed from a solid surface made from non-piezo-electric material, contacts the liquid medium to be measured and/or a transfer system. A sender sends acoustic wave energy that includes at least one Rayleigh wave, and at least part of the acoustic wave energy leaving the sender passes at least once through a mode converter on its way to the receiver, whereby this part of its wave energy is converted at least partly from a Rayleigh wave (RW) into a volume sound wave (VW) or vice versa. The physical characteristics or physical properties of the liquid are then determined using changes of at least a parameter of the Rayleigh wave.

Abstract: A method and device for making measurements of the characteristics of a fluid, particularly the milk, which flows in pulsations in a conduit. The device has a measuring region wherein at least one characteristic of the fluid is determined. The measurement is made during an optimal measuring window which constitutes a time interval while a pulsation of the fluid is received in the measuring region which contains a sensor or sensors for measuring one or more selected characteristics of the fluid, such as color, conductivity or acoustic qualities. The measuring region may be in a bypass passageway in the conduit which may be incorporated in a teat cup. The pulsations in the teat cup may be used to define an optimal measuring window for measuring one or more characteristics of the fluid as it flows in pulsations through the conduit. The sensed entry or approach of a pulsation into the measuring region may also be used to define the optimal measuring window.

Abstract: An apparatus and method for sensing chemical and/or biological analytes includes a deflectable arm of a microcantilever formed over and contacting a sensing element. A gaseous or liquid medium which may include the analyte being detected, is introduced to the sensing element. The sensing element undergoes volumetric expansion or contraction in the presence of the analyte sought to be detected, typically by adsorbing the analyte. The volumetric change of the sensing element causes the deflectable arm to deflect. The deflectable arm includes at least one measurable physical property which changes when the arm deflects. Detecting means are provided to measure the change in the physical property to determine the presence and amount of analyte present. An array of microcantilevers in which each microcantilever is dedicated to detecting a particular analyte which may be included in the medium, is also provided.

Abstract: The present invention relates to a miniature rheometer, a parallel rheometer, and improved force sensor elements which may advantageously be used in combination with the miniature rheometer and the parallel rheometer. The miniature rheometer is adapted to determine rheological characteristics of materials which are provided in the form of small quantity samples. The miniature rheometer comprises an actuating element, a sensing element and a feedback circuit to provide rebalance of the shear force applied by the sample to the sensing element, which insures an exceptional stiffness in determining the shear strain so as to allow measurements of high accuracy. The parallel rheometer of the present invention allows simultaneous measurements of a plurality of samples so as to allow of a plurality of samples within a short time period. The force sensor element according to the present invention allows simultaneous measurement of a shear force and a normal force applied to the sensor element.

Abstract: A method and apparatus for measuring properties of a fluid composition in a conduit includes a mechanical resonator connected to a measurement circuit. The measurement circuit provides a variable frequency input signal to the mechanical resonator, causing the mechanical resonator to oscillate. The input signal is then sent to the mechanical resonator and swept over a selected frequency range. The mechanical resonator's response over the frequency range depends on various characteristics of the fluid being tested, such as the temperature, viscosity, and other physical properties.

Abstract: A system and method of fluid analysis in a hydrocarbon borehole is disclosed. Acoustic energy is emitted into the production fluid downhole at a level which causes a phase transition in the fluid. The pressure associated with the phase transition is determined using the level of emitted acoustic energy. Advantageously, the determination of the phase transition pressure need not rely on mechanical means to substantially alter the volume of a sample of the fluid. An acoustic transducer can be installed either semi-permanently or permanently downhole in the well. The bubble point or the dew point can be detected. In the case of bubble point detection, the bubbles in the fluid can be detected by sensing variations in impedance of the acoustic transducer, and the level of emitted acoustic energy can determined by measuring the electrical energy used to drive the transducer. A control system for a hydrocarbon well is also disclosed.

Abstract: Methods and apparatus for screening diverse arrays of materials are provided. In one aspect, systems and methods are provided for imaging a library of materials using ultrasonic imaging techniques. In another aspect, systems and methods are provided for generating acoustic waves in a tank filled with a coupling liquid to form a disturbance that is representative of a library of materials. In another aspect of the invention, a mechanical resonator is used to evaluate various properties (e.g., molecular weight, viscosity, specific weight, elasticity, dielectric constant, conductivity, etc.) of the individual liquid elements of a library of materials.

Abstract: A method and apparatus for measuring properties of a liquid composition includes a mechanical resonator, such as a thickness shear mode resonator or a tuning fork resonator, connected to a measurement circuit. The measurement circuit provides a variable frequency input signal to the tuning fork, causing the mechanical resonator to oscillate. To test the properties of a liquid composition, the mechanical resonator is placed inside a sample well containing a small amount of the liquid. The input signal is then sent to the mechanical resonator and swept over a selected frequency range, preferably less than 1 MHz to prevent the liquid being tested from exhibiting gel-like characteristics and causing false readings. The mechanical resonator's response over the frequency range depends on various characteristics of the liquid being tested, such as the temperature, viscosity, and other physical properties.

Abstract: A method and apparatus for improving temperature stability of surface-launched acoustic wave sensors is described. The system includes a plurality of acoustic wave delay lines or resonators coated with identical films which are physically, chemically, biologically, or otherwise sensitive to one or more target chemical or biological analytes. At least one of the delay lines or resonators, referred to herein as reference channels, is used as a frequency reference to which the oscillation frequencies of the remainder of the delay lines or resonators, referred to as sensing channels, are compared. A thin coating of material that is preferably a passivation layer not sensitive to the analytes, is disposed upon the surface-launched acoustic wave sensor. The passivation layer covers sensing films on the reference channels, blocking or impeding interaction of the sensing films and the analytes thereby.

Abstract: Provided are a measurement apparatus and a measurement system comprising sample and reference microresonators, such as sample and reference quartz crystal microbalances; sample and reference heat flow sensors; and a heat sink coupled thermally to the heat flow sensors. These may be used to measure changes in one or more properties, such as mass, due to a liquid sample on a surface of a sample microresonator and also to measure heat flows from the sample on the surface of the sample microresonator by utilizing the heat flow sensors, which are coupled thermally to the corresponding sample or reference microresonators. Also provided is a method for measuring one or more properties, such as mass, of a liquid sample and the flow of heat from the sample to the heat sink by utilizing such apparatus.

Abstract: A ZrO2 porcelain comprising a cylindrical member and a flexible member made of a ZrO2 porcelain which has a relative density not lower than 95% and contains a cubic crystal at a ratio not lower than 75%, thereby exhibiting high erosion resistance and high strength.

Abstract: At least one parameter of at least one fluid in a pipe 12 is measured using a spatial array of acoustic pressure sensors 14,16,18 placed at predetermined axial locations x1,x2,x3 along the pipe 12. The pressure sensors 14,16,18 provide acoustic pressure signals P1(t), P2(t), P3(t) on lines 20,22,24 which are provided to signal processing logic 60 which determines the speed of sound amix of the fluid (or mixture) in the pipe 12 using acoustic spatial array signal processing techniques with the direction of propagation of the acoustic signals along the longitudinal axis of the pipe 12. Numerous spatial array processing techniques may be employed to determined the speed of sound amix. The speed of sound amix is provided to logic 48 which calculates the percent composition of the mixture, e.g., water fraction, or any other parameter of the mixture or fluid which is related to the sound speed amix. The logic 60 may also determine the Mach number Mx of the fluid.

Abstract: A method of quickly and safely determining the component concentrations of a three-component mixture comprising substantially sulfuric acid, hydrogen fluoride and water, which comprises measuring at least one set of three physical quantities of (1) temperature, (2) ultrasonic wave propagation velocity and (3) electric conductivity or viscosity of the three-component mixture and converting the obtained values to the component concentrations on the basis of a working curve representing the relationship between each component concentration of the three-component mixture and the three physical quantities; and a method of continuous production of hydrogen fluoride for controlling a water concentration in the reaction system by using this method.

Abstract: The invention encompasses photoacoustic apparatuses and photoacoustic spectrometry methods. The invention also encompasses sample cells for photoacoustic spectrometry, and sample cell/transducer constructions. In one aspect, the invention encompasses a photoacoustic spectroscopy apparatus, comprising: a) a sample reservoir and an acoustically-stimulable transducer acoustically coupled with the sample reservoir, the transducer comprising a detector surface having a substantially planar portion; and b) a beam of light configured to be directed through the sample at an angle oblique relative to the substantially planar portion of the detector surface to generate sound waves in the sample.

Abstract: A method and apparatus for measuring properties of a fluid composition includes a mechanical resonator connected to a measurement circuit. The measurement circuit provides a variable frequency input signal to the mechanical resonator, causing the mechanical resonator to oscillate. To test the properties of a liquid composition, the mechanical resonator is placed inside a sample well containing a small amount of the fluid. The input signal is then sent to the mechanical resonator and swept over a selected frequency range. The mechanical resonator's response over the frequency range depends on various characteristics of the fluid being tested, such as the temperature, viscosity, and other physical properties. The invention is particularly suitable for combinatorial chemistry applications, which require rapid analysis of chemical properties for screening.

Abstract: A device for detecting chemical substances includes a plurality of sensors arranged in an array. The sensors are connected to respective oscillator circuits which drive the sensors, and the oscillator circuits are coupled to a power multiplexer which provides the circuits with power according to a timing pattern such that not all of the oscillator circuits are activated at any one time. Preferably, only one oscillator circuit is activated at any given time. This multiplexing arrangement saves power and substantially eliminates cross talk between the oscillator circuits. The oscillator circuits are preferably application specific integrated circuits (ASICs), and the sensors are preferably surface acoustic wave (SAW) devices. In use, the SAW sensors are exposed to a gas, such as air, containing the chemical substance to be detected. Signals from the SAW sensors are analyzed to identify the chemical substance.

Abstract: The present invention relates to the measurement of gasoline volatility characteristics, and is directed in particular to the provision of an ultrasonic-type gasoline characteristic determination method and apparatus capable of determining the volatility characteristics with good accuracy by measuring the velocity of an ultrasonic wave in a gasoline containing alcohol or other additives and by compensating for deviations from a reference temperature, and a method for determining gasoline volatility characteristics by using an ultrasonic wave is provided, comprising the steps of transmitting an ultrasonic wave into a gasoline being measured, measuring the velocity of the ultrasonic wave in the gasoline, and determining the volatility characteristics of the gasoline from the velocity.

Abstract: The present invention is a transducer for photoacoustic detection having at least two piezoelectric elements wherein at least a first piezoelectric element has a first frequency and at least a second piezoelectric element has a second frequency. The improvement according to the present invention is that at least two piezoelectric elements are longitudinal elements for longitudinal waves; and the first frequency is different from said second frequency. In other words, the invention is a multi-frequency longitudinal transducer for photoacoustic detection.

Abstract: The chemical and/or physico-chemical determination of the ageing of a motor oil is very expensive and requires measuring methods which cannot be carried out on board a motor vehicle. The determination of only one oil condition parameter, for example the viscosity, only enables conditional statements to be made with respect to oil quality since conflicting effects may exist to varying degrees in this case. According to the invention, oil quality can be determined by a quartz base coated with a sensitive layer. The sensitive layer has a surface or volume which is adapted to an oil component and is suitable for the repeated incorporation and release of the oil component according to the concentration thereof. When the oil component is present, it is incorporated in the sensitive layer causing the resonant frequency of the layer to decrease via a mass effect or causing an effective increase of the component thickness or mass.

Abstract: A sludge blanket level is determined in a waste water treatment clarifier using sonic pulse reflections. Additionally, using similar techniques, the clarity of the waste water is determined. A sonic pulse is directed into the waste water. Echos are generated as the pulse encounters the impedance mismatches indicative of changes in the density of the water. The echos are compensated for attenuation as a function of travel time through the water, energy lost due to prior peak reflections, and are processed to remove random signals using correlation techniques. A sludge blanket is selected from the compensated echo signal as a function of the size and location of echo peaks. Additionally, the clarity is determined as a function of the area under the echo signal between two points corresponding to predefined levels in the clarifier tank.

Abstract: Disclosed is a piezoelectric resonator, a process for the fabrication thereof and its use as a sensor element, which implemented in a through-flow cell, is integratable in a measurement system for the determination of the concentration of a substance contained in a liquid and/or for the determination of the physical properties of the liquid. The piezoelectric resonator is designed plane and is provided on its surface with electric contact areas for an electrode and a counter electrode, which is connectable to a signal source as well as to a measurement device. For measuring, the piezoelectric resonator is brought into contact with the to-be-examined liquid on one side, with the resonator responding to the accumulation of the mass of the to-be-detected substance or to a change in the physical properties of the liquid by changing its resonance frequency and/or oscillation amplitude.

Abstract: Provided is a mass and heat flow measurement apparatus comprising sample and reference microresonators, such as sample and reference quartz crystal microbalances; sample and reference heat flow sensors, such as sample and reference isothermal heat conduction calorimeters; and sample and reference heat sinks coupled thermally to the heat flow sensors. The apparatus may be used to measure changes in mass due to a sample on a surface of the sample microresonator and also to measure heat flows from the sample on the surface of the sample microresonator by utilizing the heat flow sensors, which are coupled thermally to the corresponding sample or reference microresonators. Also provided is a method for measuring the mass of a sample and the flow of heat from the sample to the heat sink by utilizing such apparatus.

Abstract: Methods and apparatus for screening diverse arrays of materials are provided. In one aspect, systems and methods are provided for imaging a library of materials using ultrasonic imaging techniques. The system includes one or more devices for exciting an element of the library such that acoustic waves are propagated through, and from, the element. The acoustic waves propagated from the element are detected and processed to yield a visual image of the library element. The acoustic wave data can also be processed to obtain information about the elastic properties of the library element. In another aspect, systems and methods are provided for generating acoustic waves in a tank filled with a coupling liquid. The library of materials is then placed in the tank and the surface of the coupling liquid is scanned with a laser beam. The structure of the liquid surface disturbed by the acoustic wave is recorded, the recorded disturbance being representative of the physical structure of the library.

Abstract: An improved multi-element apparatus for detecting the presence of at least one chemical, biological or physical component in a monitored area comprising an array or single set of the following elements: a capacitive transducer having at least one cantilever spring element secured thereto, the cantilever element having an area thereof coated with a chemical having an affinity for the component to be detected; a pick-up plate positioned adjacent to the cantilever element at a distance such that a capacitance between the cantilever element and the pick-up plate changes as the distance between the cantilever element and the pick-up plate varies, the change in capacitance being a measurable variation; a detection means for measuring the measurable variation in the capacitance between the cantilever element and the pick-up plate that forms a measurement channel signal; and at least one feedback cantilever spring element positioned apart from the coated cantilever element, the cantilever element substantially unaffe