Abstract: A method and apparatus for monitoring air quality is provided.

Abstract: A particulate mass monitor includes two mass sensors, such as an optical sensor (e.g., a light scattering photometer or nephelometer) and a beta radiation attenuation sensor for substantially continuous monitoring of ambient particulate matter. During operation, the first mass sensor references the time-averaged measurement of the second mass sensor such that the second mass sensor calibrates the response of the first mass sensor. If the first sensor is an optical sensor, as it detects the presence of particulate matter within a fluid, the mass concentration measurement (e.g., signal output) provided by the optical sensor is altered using a ratio of concentration measurements of the second mass sensor and the optical sensor. The combined use of the two mass sensors provides accurate mass measurements of ambient particulate matter with a relatively high time resolution.

Abstract: A continuous flow centrifuge adapted with an insert of glass beads, sand or the like is used to concentrate cysts of microorganisms such as giardia or cryptosporidium from large volumes of water. The apparatus and methods are useful for the detection of contaminating microoorganisms in groundwater and public drinking water.

Abstract: A leak indicator including a housing that houses components of the indicator as well as a test leak, and test leaks that are suitable for integration into a leak indicator.

Abstract: The invention provides a miniaturized sensor device including a thin film membrane having a first surface and a second surface, one or more resistive thin film heater/thermometer devices disposed directly or indirectly adjacent to the first surface of the thin film membrane, and a frame disposed directly or indirectly adjacent to the second surface of the thin film membrane, wherein one or more internal surfaces of the frame define at least one cell having at least one opening. The sensor device also includes a thin film layer disposed directly or indirectly adjacent to the frame. The sensor device further includes a sensing layer disposed directly or indirectly adjacent to the thin film membrane.

Abstract: A system for making extensional measurements on a sample includes an armature, a motor drive shaft, a moveable cylinder, and a fixed cylinder. The motor drive shaft is attached to the armature. The moveable cylinder is mounted on the armature. The sample is stretched between the moveable cylinder and fixed cylinder by the rotation of the moveable cylinder around the axis of the fixed cylinder and rotation of the moveable cylinder about its own axis. The resistance of the sample produces a torque on the moveable cylinder and the fixed cylinder. The torque is measured on the moveable cylinder or on a transducer shaft attached to the fixed cylinder. The system is adaptable to a commercial rotational rheometer.

Abstract: A detector (D) for detecting the volatile signature of one or more substances, e. g. alcohol and/or cannabis, on the breath (MG) of a consumer (P), using several sensors (CT1, CT2, CT3). The sensors can comprise semi-conductors or conductive polymers. The inventive detector is equipped with a filter (F) to remove nuisance substances, e. g. water vapour, which mask the signature. The detector is advantageously portable and can be used to perform a test to evaluate (E) the consumption of a substance by the driver of a motor vehicle in relation to a reference level (N). A network of formal neurones (RN) is used to generate a database (DB) that is used to calibrate the detector.

Abstract: To conduct a fluid, the transducer has a flow tube which in operation is vibrated by an excitation assembly and whose inlet-side and outlet-side vibrations are sensed by means of a sensor arrangement. To produce shear forces in the fluid, the flow tube is at least intermittently excited into torsional vibrations about a longitudinal flow-tube axis. The transducer further comprises a torsional vibration absorber which is fixed to the flow tube and which in operation covibrates with the torsionally vibrating flow tube, thus producing reactive torques which at least partially balance torques developed in the vibrating flow tube. One of the advantages of the transducer disclosed is that it is dynamically balanced to a large extent even in the face of variations in fluid density or viscosity.

Abstract: A method for detecting leakage in a pressurised medical appliance prior to normal operation, the system including an air compressor and an inflatable bag or bladder coupled to the air compressor through the intermediary of a fill valve allowing air to pass to the bladder and a vent valve for venting the system, the fill valve and the vent valve being selectively operable during said normal operation to deliver cyclical pulses of air to inflate and deflate the bladder, the detection method comprising a) opening the fill valve to vent the system to atmospheric pressure, b) closing the vent valve, c) pressurising the system by means of the air compressor to a pre-determined threshold value, d) monitoring the pressure gradient or rise over a period of time to said threshold value and e) comparing the pressure gradient over said period of time or at intervals of time within said period of time with a pre-specified pressure gradient indicative of system integrity whereby to determine the presence or otherwise of ai

Abstract: The present invention relates to a sensor for measuring actual loads acting upon a surface of a mechanical component, wherein as a sensor an amorphous hydrocarbon layer with piezoresistive properties is used, which is preferably doped with at least one metallic and/or non-metallic element and is connected by contacts to a measuring device; the present invention further relates to the use of carbon layers having piezoresistive properties and preferably doped with metallic and/or non-metallic elements as a sensor for load measurements, as well as to a method of measuring actual loads at stressed surfaces of mechanical components, wherein as a measuring sensor an amorphous carbon layer preferably doped with metallic and/or non-metallic elements is used.

Abstract: An approach to determine cantilever movement is presented. An observer based state estimation and statistical signal detection and estimation techniques are applied to Atomic Force Microscopes. A first mode approximation model of the cantilever is considered and a Kalman filter is designed to estimate the dynamic states. The tip-sample interaction is modeled as an impulsive force applied to the cantilever in order to detect the presence of sample. A generalized likelihood ratio test is performed to obtain the decision rule and the maximum likelihood estimation of the unknown arrival time of the sample profile and unknown magnitude of it. The use of the transient data results in sample detection at least ten times faster than using the steady state characteristics.

Abstract: A temperature control apparatus for a humidity sensor is provided for preventing impurities from sticking on a sensor element, while protecting the sensor element from cracking due to the humidity sensor heated by a heater in the presence of condensation, to maintain a high detection accuracy of the humidity sensor. The temperature control apparatus is configured to control the temperature of a sensor element of a humidity sensor disposed in an exhaust passage of an internal combustion engine for detecting the humidity within the exhaust passage. The temperature control apparatus comprises a heater for heating the sensor element, a temperature sensor for detecting the temperature of the sensor element, and an ECU for controlling a heating amount of the heater to bring the detected temperature of the sensor element to a first predetermined temperature during an operation of the internal combustion engine.

Abstract: A leak detector comprises a high vacuum envelope connected with a vacuum pump to bring the vacuum envelope to a pressure sensibly lower than ambient pressure. At least a portion of the envelope is separated from an external environment through a quartz membrane associated with an electrical resistor, which heats the membrane to a sufficient temperature in order to make it permeable to a corresponding test gas (in particular, helium). In operation, an electronic control unit detects variations in the current absorbed by the vacuum pump and consequently signals the test gas diffusion into the chamber and hence the existence of a leak. A sampling line with a sampling pump disposed therein is connected to a probe for the intake of gas directed to expose to the membrane. The gas is discharged to the outside through a discharge line. A system for switching between the gas intake and exhaust is provided, in order to quickly eliminates any test gas trace from said detector.

Abstract: A method and apparatus for measuring relative humidity of a mixture that provides a quick response time for thermal lag while affording protection to fragile sensors. In one aspect, the invention is an apparatus comprising: a chamber having a membrane covering an opening in the chamber, the membrane being permeable to water vapor while impermeable to liquid water; a humidity sensor for measuring relative humidity of the mixture within the chamber; a first temperature sensor for measuring a temperature relating to the mixture within the chamber; a second temperature sensor for measuring temperature of the mixture at a point exterior to the chamber; and a processor for receiving signals representing the measurements taken by the humidity sensor, the first temperature sensor, and the second temperature sensor and programmed to calculate relative humidity of the mixture at the point exterior to the chamber as a function thereof.

Abstract: Dynamic nanomechanical analysis of a sample is performed by using a cantilever probe that interacts with the sample using a force applied across a wide range of frequencies that includes frequencies greater than 300 Hz. The motion of the cantilever probe is detected in response to the applied force over the range of frequencies and analyzed over at least a portion of the wide range of frequencies to determine a mechanical response of the sample, preferably including quality factor and modulus of the sample. The analysis of the motion of the cantilever probe is preferably performed in terms of amplitude, phase, and frequency of both the probe and the sample and preferably, where the applied force is analyzed to determine both a real and an imaginary modulus of a mechanical response of the sample. Preferably, the force is applied so as to produce a minimum of phase and amplitude response variation in the absence of the sample.

Abstract: A gas detector having an intake to let in the gas to be detected and detecting the gas let in through the intake by a gas sensor, in which a porous film is horizontally arranged over the gas intake, in order to prevent the gas permeability of the porous film from being affected by water, oil and/or dust riding on the porous film, wherein a water-repellant and oil-repellant porous film is horizontally provided in a stretched state over the upper end of the intake, and the outside of the outer circumferential edge of the porous film is so structured as to allow liquid on the porous film to fall externally.

Abstract: The present invention relates to a sensor apparatus configured to detect the presence of a gas, such as a tracer gas and a leak detection apparatus configured to detect the presence of a tracer gas and indicate the location of a leak. The leak detection apparatus may further be configured to quantify the leak rate at the leak location.

Abstract: A leak detection instrument may comprise a housing, a gas sensor supported relative to the housing, an AE sensor for generating a sound detection input signal upon exposure to gas leakage, processing circuitry for producing output signals, and an output device. The AE sensor may include an elongated mounting member, an AE sensor housing supported by the mounting member, and an AE sensor disposed therein. Improvements to leak detection instruments, an AE sensor mounting assembly and a method of monitoring a device to ascertain leakage of a target gas therefrom are also provided.

Abstract: A gas sensor device including a semiconductor substrate; one or more catalytic gate-electrodes deposited on a surface of the semiconductor substrate; one or more ohmic contacts deposited on the surface of the semiconductor substrate and a passivation layer deposited on at least a portion of the surface; wherein the semiconductor substrate includes a material selected from the group consisting of silicon carbide, diamond, Group III nitrides, alloys of Group III nitrides, zinc oxide, and any combinations thereof.

Abstract: The invention relates to a chamber (2) for gas sensors (9) to be used in a device (1) for detecting aromas or odors. The chamber (2) comprises three portions (5, 6, 7) in which there is a uniform, turbulence-free flow (F) of gas or vapors to be analyzed, and at least one gas sensor (9) positioned in the central portion in such a way as to be immersed in and to laterally and tangentially interact with the flow (F). The chamber (2) also comprises a heating and temperature regulating device (16, 17). The invention also relates to an odor detection method which comprises a step in which a uniform, turbulence-free flow (F) of gas or vapor interacts with a gas sensor (9) laterally and tangentially.