Abstract: A inductive conductivity sensor for measuring conductivity of a fluid includes a housing supporting a controlled impedance loop and a transducer. The transducer includes a driver for inducing a first current into the fluid adjacent the housing, and for inducing a second current into the controlled impedance loop. The transducer further includes a detector for inductively measuring the first and second currents.

Abstract: An instrument that analyzes chemical properties of a specimen includes a probe that is used in place on the specimen for spectroscopic analysis. The probe has a probe body with a proximal end and a distal end, and a first optical fiber extends from the proximal to the distal ends. A temperature sensor is included in the probe body and is used so insure that the probe does not exceed a rated temperature limit or to monitor specimen temperature while, simultaneously, chemical composition information of the specimen is transmitted by the optical fiber. The probe can be inserted into a container holding the specimen and can yield both temperature and chemical composition information. The probe includes a plurality of metal coated fibers with the distal ends of the fibers positioned inside a bore in the probe. Braze material is placed on the probe near the bore and the braze material is then brazed to the metal coating on the ends of the fiber.

Abstract: A flame ionization detector burner, includes a housing having a generally cylindrical flame cavity therein extending along a generally longitudinal axis of the housing and a housing exterior with intake passageways communicating between the housing exterior and the flame cavity for passing fuel, air and sample flows into the flame cavity and an exhaust passage communicating between the housing exterior and the flame cavity for passing exhaust gasses out of the flame cavity. A burner carried in the housing cavity receiving the fuel, air, and sample flow generates a flame to ionize the sample. An ion collector plate spaced away from the burner carried in the time cavity collects sample ions and provides an electrical output representative of the sample ions to the housing exterior via an electrical feedthrough between the flame cavity and the housing exterior. The housing includes at least two cylindrical sidewalls removably joined together along the general longitudinal axis of the housing.

Abstract: The invention pertains to a method for measuring the concentration of dissolved gases in a liquid [(39)], especially of CO2 in beverages, in which the liquid [(39)] is passed across the retentate side [(140)] of a membrane [(14)] that is at least partially permeable to the dissolved gas, and [in which] the volumetric flow of the permeated gas on permeate side [(16)] of the membrane [(14)] is determined, the temperature of the liquid [(39)] is measured, and the concentration of the dissolved gas in the liquid [(39)] is calculated from these values. In this, the thickness of the membrane [(14)] can be pre-selected as a function of the flow rate of the liquid [(39)] flowing along the retentate side [(140)].

Abstract: An electrochemical sensor structure includes a housing having an inner surface defining a housing cavity. The sensor also has an inner body having an outer surface. The outer surface of the inner body and the inner surface of the housing have engaging portions which directly engage one another to form a channel therebetween. The channel defines an ionic junction in the sensor.

Abstract: A gas chromatograph includes a manifold having a plurality of gas conduits formed therein. A valve module includes a support, a first valve mounted to the support and having a plurality of ports, and a column coupled to the support and being in communication with a port in the first valve. The valve module is pluggably engagable with the manifold. A detector is coupled relative to the column to detect gasses expelled from the column.

Abstract: An analyzer for analyzing chemical properties of a specimen using optical coupling and sensing, has a narrow band light source and an optical probe that is in contact with the specimen. Detectors are used for providing electrical outputs as a function of a parameter of the specimen, and an optical path couples light from the light source to the probe and also couples Raman scattered light from the specimen and Rayleigh scattered light from the specimen to separate detectors. An analyzer circuit is coupled to the detectors to provide outputs as a function of the electrical signals received, and one of the detectors is connected to a signal conditioning circuit for controlling the input of the light source and includes an asymmetric discrimination circuit configured to distinguish positive going fluctuations from negative going fluctuations in the output from the detector.

Abstract: An industrial process sensor includes a proximal end, a distal end, a longitudinal axis and an outer diameter surface. A cam follower surface is recessed into the outer diameter surface. A diameter reduction is formed on the outer diameter surface, between the cam follower surface and the distal end. The diameter reduction defines an annular process sealing shoulder that faces the distal end and lies in a plane intersecting the longitudinal axis. A sensor element is carried at the distal end. A cable is electrically coupled to the sensor element and extends from the proximal end.

Abstract: A solid electrolyte gas analyzer includes an analyzer circuit housed in an electronics housing and a probe housing for immersion in the gas of interest. The electronics housing mounts directly to the probe housing, preferably through a standoff. The analyzer circuit is powered by an AC line input and includes a switching power supply to convert the AC line input to DC power useable by the analyzer circuit. The analyzer circuit also includes a heater circuit controlling a heater in the probe housing. The power supply and the heater circuit automatically adjust to different AC line input voltage levels. The switching power supply efficiently supplies DC power to other portions of the analyzer circuit with little heat generation.

Abstract: A method and apparatus for providing output emission data corresponding to output emissions from a source of emissions includes a sensing emission monitoring system that senses the output emissions directly from the source of emissions and a predictive emission monitoring system that predicts the output emissions from the source of emissions. The sensing emission monitoring system provides a first set of output values indicative of the output emissions, while the predictive emission monitoring system provides a second set of output values indicative of the output emissions. The system checks the operating state of the sensing emission monitoring system and generates output emission data from the first set of output values if the sensing emission monitoring system is operable and from the second set of the output values if the sensing emission monitoring system is inoperable.

Abstract: An instrument that analyzes chemical properties of a specimen using optical sensing provides a laser source with an optical fiber channel that carries light from the source to a probe. The probe has a receiving optical fiber and has an emitting optical fiber that carries Raman-scattered light from the specimen. The emitting optical fiber has a metal buffer layer. A spectral detector receives light from the receiving optical fiber in the probe. A filter module includes a filter that transmits the wavelength of the laser source but blocks wavelengths longer than the source between the source and the emitting optical fiber or the probe. The filter module is coupled to the probe by a linking optical fiber.

Abstract: An apparatus for measuring ion concentration of a solution includes an ion sensitive field effect transistor (ISFET), a reference device, an ISFET control circuit, a memory, a measurement circuit and a diagnostic circuit. The ISFET has a drain, a source, an ion sensitive gate region and a plurality of device characteristics. The reference device is separated from the gate region by a sample solution. The ISFET control circuit is coupled to the ISFET and operates the ISFET at a drain-source voltage V.sub.DS and at n successive drain currents I.sub.Di and corresponding gate-source voltages V.sub.GSi, wherein i is an integer from 1 to n and n is an integer greater than 1. The memory stores the plurality of device characteristics and the n successive drain currents I.sub.Di and gate-source voltages V.sub.GSi. The measurement circuit measures ion concentration of the solution as a function of at least one of the n successive drain currents I.sub.Di and gate-source voltages V.sub.

Abstract: The method and apparatus for measuring a content of vaporous hydrogen peroxide in a gaseous medium within an enclosure includes a irradiating a portion of the gaseous medium with light, measuring an absorbance of light in a selected near-infrared wavelength range, and calculating the content of vaporous hydrogen peroxide from the measured absorbance of light.

Abstract: A photoionization detector includes a brittle substrate having a void micromachined therein with a void inlet and a void outlet. First and second electrodes are disposed in the void. An ultraviolet transparent member covers at least a portion of the void in which the electrodes are disposed. A gas sample passes through the void and is exposed to ultraviolet radiation from a UV source. Ionization of the sample is measured as current flowing between the electrodes.

Abstract: An Ion-sensitive Field Effect Transistor (ISFET) sensor for sensing ion activity of a solution includes a substrate and an ISFET semiconductor die. The substrate has front surface exposed to the solution, a back surface opposite to the front surface and aperture extending between the front and back surfaces. The ISPET semiconductor die has an ion-sensitive surface with a gate region. The ion-sensitive surface is mounted to the back surface such that the gate region is exposed to the solution through the aperture.

Abstract: A gas chromatograph includes a manifold having a plurality of gas conduits formed therein. A valve module includes a support, a first valve mounted to the support and having a plurality of ports, and a column coupled to the support and being in communication with a port in the first valve. The valve module is pluggably engagable with the manifold. A detector is coupled relative to the column to detect gasses expelled from the column.

Abstract: A modular analyzer system consists of a control device and one or more functional analyzer modules linked to the control device. The analyzer modules include FID, NDIR, chemiluminescence and paramagnetic analyzers. Each analyzer module includes a microprocessor having all menus necessary for the operation of the analyzer. Menus are coded and transmitted in real time by providing the control device with a dictionary of menu phrases which are coded and the codes maintained in a code index at each analyzer module and at the control device. Since menus are maintained at the analyzer module and not transmitted until called for, there is no need to store specific menus at the control device. New modules can be easily added to the system and any phrases not already included in the phrase dictionary are downloaded to a supplemental dictionary when the new module is added. Data is displayed in the form called for by the analyzer menu and data from several analyzer modules can be displayed simultaneously.

Abstract: An apparatus for measuring the BTU content of a gas includes a source of combustion air, a detector and a sample loop or tube connected to a six-port switching valve. The switching valve allows accurate and repeatable quantities of the gas to be obtained and mixed with the combustion air. In a second embodiment, the apparatus includes a second switching valve to obtain samples of the gas at a second pressure and calculate the BTU content at the second pressure. By measuring the BTU content at two different pressures, a quantity related to the volumetric flow of the gas between the two pressures can also be calculated.

Abstract: A measuring probe measures a parameter with a sensor. The sensor provides a sensor output signal related to a measured value. An amplifier section receives the sensor output signal and provides an amplifier output signal. An integrator has an input and an integrator output related to an integration of the input. Switching circuitry receives the amplifier output signal and a reference signal and has an output connected to the input of the integrator. Controller circuitry coupled to the switching circuitry connects the amplifier output to the integrator input during a sampling time, and the reference signal to the integrator input during a conversion time. The conversion time is related to the sensor output signal and is measured to obtain a digital representation of the sensor output.

Abstract: A gas analyzer arrangement for detecting the presence or quantity of a gas of interest includes a source of electromagnetic radiation for directing a light beam through a light conditioning device such that the light beam is collimated into a parallel beam of light. The conditioned light beam is then directed through a gas sample cell which contains a sample of the gas of interest. The gas of interest has associated therewith, vibrational rotational absorption lines specific to that gas and which are effective for altering the light beam according to the absorption characteristics thereof. The altered light beam is then directed to a birefringent etalon device which has been sized specifically to match those absorption lines of the gas of interest.