Abstract: The present invention provides a pump device 50 which is usable to dilute a sample 52 before analysis. A first pump 54 pumps the sample to a mixing region 58 where it mixes with a diluent 66. A second pump 64 pumps the diluted sample to the analysis instrument. The flow of the diluent to the mixer is equal to the difference of the flow of the sample to the mixer and the flow of the diluted sample to the instrument. Pumps 54 and 64 are independently controllable by a controller unit which is arranged so that data from the instrument can be used to determine the dilution factor of the sample. Thus, the controller can control this dilution factor in real time, upon receipt of such data from the instrument, by change either one of (or both) the pump's flow rate.

Abstract: A parallel-plate diffusion gas dehumidifier has a treatment zone having at least one water-permeable membrane. The gas dehumidifier includes an untreated gas inlet, a treatment zone bounded by water-permeable membranes, a support structure for the membranes, access to a source of vacuum, and a dehumidified gas outlet. The cross section of the treatment zone may be provided in various shapes, for example, rectangular. The gas dehumidifier inlet and outlet include flow transitions that minimize the obstruction of particles passing through the dehumidifier. The dehumidifier may be used in particle sampling systems to dehumidify the sample gas prior to introducing the sample gas to a mass measuring device and mass flow controller. Methods of operating the gas dehumidifier and the particle sampling system are also provided.

Abstract: A method of enhancing spectral data such as a frequency, wavelength or mass spectrum comprises applying an inverse Fourier Transform to the data in the frequency, wavelength or mass spectrum, zero-filling and, optionally, apodizing that inverse transform data, and then applying a Fourier Transform to convert the inverse data back into the frequency, wavelength or mass domain. The resultant processed spectrum provides a more accurate indication of peak location, shape and height.

Abstract: Turbulent mixing condensation devices, methods, and systems adapted to condense a working fluid on particles from a sample gas to enlarge the particles for subsequent detection are provided. The device includes a vapor generator adapted to produce a working-fluid saturated carrier gas and a condensation chamber. The working-fluid saturated carrier gas is mixed with a sample gas containing particles to be detected and is then introduced to the condensation chamber. The operating conditions are controlled to enhance the condensation of the working fluid on the particles. The particles are typically forwarded to a particle detection device to detect at least one characteristic, for example, the size, of the particles. The flow of carrier gas to the vapor generator may be regulated to vary the degree of saturation of the carrier gas with working fluid.

Abstract: Transducer assemblies and methods of replacing having a housing, a removable diaphragm, and a sealing diaphragm. The transducer assembly may be used with a spool piece to prevent fluid from escaping from the spool piece when parts of the transducer assembly are removed.

Abstract: A method for determining a velocity of a flowing fluid includes estimating a Reynolds number for the flowing fluid; comparing the estimated Reynolds number with a selected range; and determining the velocity of the flowing fluid based on a flow model selected from a laminar flow model, a turbulent flow model, and a partial laminar flow model. An ultrasonic flow meter includes a plurality pairs of transducers configured to form a plurality of measurement paths in a pipe, wherein the plurality of measurement paths are arranged asymmetrically relative to a centerline of the pipe.

Abstract: A parallel-plate diffusion gas dehumidifier has a treatment zone having at least one water-permeable membrane. The gas dehumidifier includes an untreated gas inlet, a treatment zone bounded by water-permeable membranes, a support structure for the membranes, access to a source of vacuum, and a dehumidified gas outlet. The cross section of the treatment zone may be provided in various shapes, for example, rectangular. The gas dehumidifier inlet and outlet include flow transitions that minimize the obstruction of particles passing through the dehumidifier. The dehumidifier may be used in particle sampling systems to dehumidify the sample gas prior to introducing the sample gas to a mass measuring device and mass flow controller. Methods of operating the gas dehumidifier and the particle sampling system are also provided.

Abstract: A particulate mass monitor includes a controller that monitors a change in a resonant oscillation frequency of a taut metallic membrane, as caused by deposition of the particulate matter on the metallic membrane. The metallic membrane, such as a foil or metallized plastic film, is substantially mechanically stable under tension. Application of a tension to the periphery of the metallic membrane generates a substantially constant tension within the membrane, thereby allowing the particulate mass monitor to detect a particulate mass concentration of the air sample with a relatively high degree of accuracy. Additionally, the particulate mass monitor includes a membrane transporter that automatically advances the metallic membrane within the particulate mass monitor. The membrane transporter minimizes the necessity for manual replacement of the metallic membrane over time and allowing long term, unattended operation of the particulate mass monitor.

Abstract: A test circuit employs use of first and second switches to operably charge a capacitor to over 500 volts and, thereafter, discharge energy stored in the capacitor to test an over-voltage protection circuit associated with a pin of a semiconductor device. When switched by a controller, the first switch couples a high voltage source to charge a capacitor. After completing this charge phase, the controller opens the first switch, decoupling the high voltage source from the capacitor. The controller then activates the second switch to couple the capacitor to the pin of the semiconductor device. During this discharge phase, energy in the capacitor discharges through the protection circuit of the semiconductor device. Use of a high-voltage dry reed vacuum relay as the first switch provides better isolation of the high voltage source from the capacitor, avoiding a presence of an unwanted residual voltage component in a simulated ESD test pulse.

Abstract: A clip is used with a pilaster assembly, where the clip is snap-fit into the slots of the pilaster, so that the clip is retained when inserted into the slots. This provides the advantage that the clips tend not to fall out due to bumps or vibrations such as those that can occur, for example, during transport of a cabinet having the pilasters and clips.

Abstract: A flood gun 10 for charge neutralization of an analysis region Ra of a sample S downstream of the flood gun, comprising: a first source 30 of electrons; a second source 50 of positively charged particles; and an extraction and focusing assembly 60,64, arranged to: (i) extract a first, electron beam from the first source and focus the first beam to a first flood area Ae at the analysis region; and (ii) extract a second, positive particle beam from the second source and focus the second beam to a second flood area Ai at the analysis region. The electron beam and the positive particle beam may both be extracted and focused simultaneously, in a single mode of operation or, alternately, in a dual mode of operation. A corresponding method of providing charge neutralization and a spectroscopic system for secondary particle emission analysis are disclosed.

Abstract: The present invention provides a pump device 50 which is usable to dilute a sample 52 before analysis. A first pump 54 pumps the sample to a mixing region 58 where it mixes with a diluent 66. A second pump 64 pumps the diluted sample to the analysis instrument. The flow of the diluent to the mixer is equal to the difference of the flow of the sample to the mixer and the flow of the diluted sample to the instrument. Pumps 54 and 64 are independently controllable by a controller unit which is arranged so that data from the instrument can be used to determine the dilution factor of the sample. Thus, the controller can control this dilution factor in real time, upon receipt of such data from the instrument, by change either one of (or both) the pump's flow rate.

Abstract: A metal detector has a circular excitation coil (10) through which foodstuffs to be tested (65) pass, on a conveyor belt (40). The excitation coil (10) is excited by a stable oscillator (50) and the lines of flux generated by the excitation coil (10) link two receiver coils (20, 30) equidistantly spaced either side of the excitation coil (10). As a foodstuff (65) having a foreign ferromagnetic or electrically conductive object therein passes through the receiver coils (20, 30), a voltage is induced in them. This induced voltage is phase compensated. The change in amplitude or frequency of the oscillator (50) as the foodstuff (65) moves through the excitation coil (10) is also passed to the processor (70) which removes the artifacts from the detector signal caused by the volume of the foodstuff (65) itself. The resultant signal, which was previously swamped by the effect of the volume of the foodstuff itself, can then be detected and the foodstuff can be removed from the conveyor (40).

Abstract: A pumping apparatus (50) which isolates a sample (52) from a pump (72), thereby circumventing the so-called “memory effect” problem. The sample is pumped into an intermediary, or buffer region (64) using a first pump (54). The sample is displaced from this buffer region by pumping a second fluid (74) into the buffer region using a second pump (72). When the sample is displaced from the buffer region it proceeds to a mixer (78) where it can be diluted before analysis. The second pump is required to operate with a high degree of accuracy so that the sample is diluted by a consistent amount. Preferably, the second pump is a highly accurate piston pump.

Abstract: A multi-way radiation monitoring and detection system is capable of detecting a radiation source on or within traffic that can travel within M adjacent traffic ways, where M is an integer equal to or greater than a value of 2. The radiation detection system comprises a set of (M+1) radiation detector assemblies with individual radiation detector assemblies of the set of (M+1) radiation detector assemblies respectively positioned at each of two sides of each of the M adjacent traffic ways. A set of M controllers is included and each controller is associated with a respective traffic way of the M adjacent traffic ways. Each controller is coupled to the respective individual radiation detector assemblies positioned at the two sides of the traffic way to which that controller is associated, such that two controllers associated with two adjacent traffic ways couple to the individual radiation detector assembly positioned between those two adjacent traffic ways.

Abstract: A flood gun 10 for charge neutralization of an analysis region Ra of a sample S downstream of the flood gun, comprising: a first source 30 of electrons; a second source 50 of positively charged particles; and an extraction and focusing assembly 60,64, arranged to: (i) extract a first, electron beam from the first source and focus the first beam to a first flood area Ae at the analysis region; and (ii) extract a second, positive particle beam from the second source and focus the second beam to a second flood area Ai at the analysis region. The electron beam and the positive particle beam may both be extracted and focused simultaneously, in a single mode of operation or, alternately, in a dual mode of operation. A corresponding method of providing charge neutralization and a spectroscopic system for secondary particle emission analysis are disclosed.

Abstract: A proximity sensor module includes a housing; and a proximity sensor disposed in the housing, wherein the proximity sensor comprises a sensor plate configured to contact inside of the housing such that substantially no gap exists between the sensor plate and the housing. The housing may be a substantially explosion-proof housing. The housing may include two members coupled by a thread engagement, wherein a sensor plate of the proximity sensor is placed off-center with respect to an axis of rotation for the thread engagement.

Abstract: An ion source for use in a mass spectrometer includes an electron emitter assembly configured to emit electron beams, wherein the electron emitter assembly comprises carbon nanotube bundles fixed to a substrate for emitting the electron beams, a first control grid configured to control emission of the electron beams, and a second control grid configured to control energies of the electron beams; an ionization chamber having an electron-beam inlet to allow the electron beams to enter the ionization chamber, a sample inlet for sample introduction, and an ion-beam outlet to provide an exit for ionized sample molecules; an electron lens disposed between the electron emitter assembly and the ionization chamber to focus the electron beams; and at least one electrode disposed proximate the ion-beam outlet to focus the ionized sample molecules exiting the ionization chamber.

Abstract: A fluid flow transducer module includes a fluid flow conduit having an inlet for receiving fluid, a transducer for measuring rate of flow of the fluid, an interface in communication with the transducer and adapted to receive rate of flow measurements from the transducer, the conduit having an outlet for flowing the fluid from the transducer to a reservoir, the outlet extending transversely of the conduit, a housing for the conduit, conduit inlet, conduit outlet, and transducer, the housing having opposed first and second walls, each wall having an opening for the outlet therein, and at least one of the walls being adapted for stacking engagement with a second transducer module of a same structure, such that the outlets of the modules are aligned to form a common conduit, and the interconnected modules form a flow transducer assembly having a plurality of fluid flow conduits and transducers.

Abstract: A spectroscopic analyser and method of use, for surface analysis spectroscopy, are disclosed. The spectroscopic analyser 10 has a time-of-flight (TOF) spectrometer which analyses secondary electrons emitted from a surface of a sample 30 on excitation by an irradiation source 40. The TOF spectrometer includes a gate 50, which receives and selectively passes a proportion of the secondary electrons by pulsed deflection or retardation of the electron beam using gating members 55. In that manner one or more pulses of electrons enter a magnetic field-free flight tube 90 and reach a detector 120 downstream of the gate 50. The flight times, and therefore energies, of the detected electrons through the flight tube 90 are thereby detected. A curved electron mirror 100 may be used to increase the flight path of the pulsed electrons in the flight tube 90, thereby increasing the spread of each electron pulse within the analyser 10.