Abstract: A sensor is provided having a diaphragm. One side of the diaphragm is arranged to be exposed to a fluid, to measure a characteristic of the fluid. Two supports are mounted on the diaphragm and a resonator is provided on the supports. The proportion of energy transferred from the resonator to the diaphragm is variable for the sensor to be used either as a viscosity/density sensor or as a pressure sensor.

Abstract: A resonant sensor is disclosed which may be arranged to measure the pressure of a fluid. The resonant sensor comprises a diaphragm which may be exposed to a fluid; two supports provided on the diaphragm and a resonator having at least two beams with each beam being suspended between the two supports. The ends of each beam are attached to a corresponding support at more than one point. By attaching each end of the beams to a support at more than one point, the moments and reaction forces to which the support is subjected may be balanced so that distortion of the support and diaphragm due to vibration of the resonator beams is reduced. Consequently, the resonant sensor is able to provide more precise measurements.

Abstract: A thermal sensor having a robust mechanical connection between a thermal sensor housing and thermal sensor tube is provided having a cross-sectional shape configured to provide a reduced thermal conductivity between the sensor and the housing.

Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.

Abstract: A miniature pressure transducer is disclosed which is able to operate at high temperatures. The pressure transducer is provided on a substrate comprising an elongate silicon base portion with one or more contact areas formed at one end and a diaphragm formed at the opposite distal end. A plurality of piezoresistive elements are provided on the diaphragm, preferably in a Wheatstone Bridge arrangement, and connected to the contact areas using interconnects. The diaphragm extends across substantially the entire effective width of the elongate base portion providing a compact width while still maintaining a sensitive pressure sensing capability.

Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.

Abstract: In one embodiment of the spectroscopy method, the method comprises the steps of modulating the wavelength of a monochromatic radiation at a modulation amplitude and a modulation frequency; determining a first variable representative of an absorbance of an analyte in a sample; and demodulating by phase-sensitive detection the first variable at a harmonic of the modulation frequency to produce a harmonic spectrum of the analyte. In one embodiment of the spectroscopy apparatus, the apparatus comprises a laser diode integrated with a first photodetector configured to detect an intensity of a backward emission from the laser diode and act as a reference detector; a second photodetector configured to detect an intensity of laser radiation exiting a sample; and electronic circuitry coupled to the laser diode and the photodetectors, configured to acquire and process spectra of the sample.

Abstract: In one embodiment, a multi-path ultrasonic flow meter for determining the flow rate of a fluid in a conduit is disclosed comprising at least two transducer pairs attached to the conduit at two chord locations, one greater than and one less than a mid-radius chord, wherein the composite ratio the two path velocities to the flow rate is substantially constant over the range of Reynolds numbers. In another embodiment, a method of determining the flow rate of a fluid in a conduit is disclosed comprising the steps of determining a composite velocity by determining a weighted average of a plurality of path velocities, determining a chord velocity ratio based on the path velocities, determining a profile correction factor based on the composite velocity and the chord velocity ratio, and determining the flow rate based on the composite velocity and the profile correction factor.

Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.

Abstract: Methods and systems for detecting a temperature TO of a remote object are provided. The method includes storing in memory, a lookup table relating an output voltage of an infrared sensor to a temperature sensed by the infrared sensor V(TO, TA), determining a temperature sensor voltage output corresponding to a temperature TA proximate the infrared sensor, determining a first voltage as a function of the temperature TA proximate the infrared sensor and a reference temperature TREF, V(TA, TREF), determining a second voltage as a function of the temperature of the object TO and the reference temperature TREF, V(TO, TREF) by combining the determined temperature sensor voltage output and the first voltage, and determining a temperature of the object TO from the lookup table using the second voltage.

Abstract: Methods and systems for detecting a proximity of an object are provided. The method includes receiving a first beam of radiation from a first field of view directed onto a first detector and a second beam of radiation from a second field of view directed onto a second detector wherein the second beam is angularly displaced from the first beam by a predetermined amount, generating a first output signal from the first detector correlative to the energy received from the first beam and a second output signal from the second detector correlative to the energy received from the second beam, and outputting a proximity signal indicative of the proximity of an object when a differential between the first and second output signals exceeds a predetermined threshold.

Abstract: A flow measurement system including at least first and second ultrasonic transducers coupled to an existing conduit, a damping material about the conduit between the first and second ultrasonic transducers to prevent crosstalk, a damping material about the conduit upstream of the first ultrasonic transducer to attenuate system background noise travelling in the conduit at large, and a damping material about the conduit downstream of the second ultrasonic transducer to attenuate system background noise travelling in the conduit at large.