Abstract: Aspects of the present invention include systems, devices, and methods of surface chemical analysis of solid samples, and particularly it relates to methods of chemical analysis of molecular compounds located either on or within thin surface layer of solid samples. Even more particularly, aspects of the present invention relate to systems, devices, and non-destructive methods combining both high sensitivity and high spatial resolution of analysis of chemical compounds located or distributed on the surface of solid samples with obtaining most important information regarding vibration spectra of atoms and molecular groups contained in thin surface layer of solid samples. These objectives are realized by implementation of computer-assisted systems that carefully regulate the motion of, and force applied to probes of atomic force microscopes.

Abstract: A dynamometer may be configured to simulate the rotating inertial characteristics of a wheel-tire assembly slipping relative to a road surface and having rotating inertial characteristics different than the rotating inertial characteristics of the wheel-tire assembly being simulated.

Abstract: A test stand may include a clutch operatively arranged with a dynamometer and a flywheel. The test stand may further include a controller configured to control the clutch to decouple a rotating inertia of the dynamometer from a rotating inertia of the flywheel such that the rotating inertia of the flywheel exhibits a desired rotating inertia.

Abstract: A system of sampling a fluid comprises a fluid separator having a central axis. The fluid separator includes an insulating sleeve. In addition the fluid separator includes a separator assembly coaxially disposed within the sleeve. Further, the fluid separator includes an annulus radially disposed between the sleeve and the separator assembly. The separator assembly includes a conduit, a support rod coaxially disposed within the conduit, and a plurality of separator members coupled to the support rod within the conduit.

Abstract: A dynamometer may be configured to simulate the rotating inertial characteristics of a wheel-tire assembly slipping relative to a road surface and having rotating inertial characteristics different than the rotating inertial characteristics of the wheel-tire assembly being simulated.

Abstract: A test stand may include a clutch operatively arranged with a dynamometer and a flywheel. The test stand may further include a controller configured to control the clutch to decouple a rotating inertia of the dynamometer from a rotating inertia of the flywheel such that the rotating inertia of the flywheel exhibits a desired rotating inertia.

Abstract: A partial flow sampling system includes a system inlet for receiving an exhaust sample flow from a sample inlet probe and transfer line. The system further includes a dilution air control system for controlling a dilution air flow rate, and a mixer. The mixer receives and mixes the exhaust sample flow and the dilution air flow to produce a mixture flow. A total flow control system controls the mixture flow rate. An orifice flow meter installed at the system inlet measures the exhaust sample flow rate in. real-time. This provides accurate sample flow measurements over a wide range of dilution ratios and sample ratios.

Abstract: A particle generating system includes an aerosol generator, an ejector diluter, and an aerosol diluter. The ejector diluter receives the generated aerosol and dilutes the aerosol to an expected raw concentration. The aerosol diluter further dilutes the aerosol to a concentration in the range of 0% to 100% of the expected raw concentration. The aerosol diluter includes a mini cyclone for diluting the aerosol. The particle generating system may be configured to provide variable concentrations of monodisperse or polydisperse aerosols for instrument calibration. The system may provide constant concentrations in the range of 0% to 100% of the raw concentration. The mini cyclone makes the system compact, and the system may be portable.

Abstract: An acoustic flowmeter calibration method and sampling system address a variation in acoustic transducer delay time with increasing temperature. In one aspect, calibration of the path length between the sending and receiving transducers and calibration of the transducer delay time over a wide temperature range are optimized. In another aspect, the flowmeter output is temperature compensated based on the exhaust flowmeter gas temperature. These two aspects may be embodied in an ultrasonic flowmeter for exhaust gas measurement individually or in combination in accordance with the invention.

Abstract: A particle generator is able to generate pure particles for solid or liquid materials with melting points over several hundred degrees Celsius. The material is heated to generate the vapor in a small chamber. Heated nitrogen or some inert gas is used as the carry gas to bring the mixture into a dilution system. As the super saturation ratio of the material is large enough and over a critical value, particles are formed in the dilution system by homogenous nucleation, and grown in the same dilution system as well. The different size distributions and concentrations of the particles can be obtained by varying dilution parameters, such as residence time and dilution ratio.

Abstract: An acoustic transducer includes an acoustic pulse generator, an impedance matching layer, and a thermal management system. The thermal management system is mounted to the matching layer to transfer heat from the matching layer, and is formed of a high thermal conductivity material relative to the matching layer. The thermal management system is arranged along the matching layer such that substantial heat is transferred to the environment from the thermal management system without excessive temperature increase at the pulse generator.

Abstract: An acoustic transducer for measuring a property of a fluid includes an acoustic pulse generator and buffer assembly. The buffer assembly is between the pulse generator and the fluid. The buffer assembly is composed of a core and a sleeve shrink fitted over the core to form a cladding layer. The cladding layer reduces dispersion of the acoustic pulses traveling through the core.

Abstract: An acoustic transducer for measuring a property of a fluid includes an acoustic pulse generator and buffer assembly. The buffer assembly is between the pulse generator and the fluid. The buffer assembly is composed of a core and a sleeve shrink fitted over the core to form a cladding layer. The cladding layer reduces dispersion of the acoustic pulses traveling through the core.

Abstract: An acoustic transducer includes an acoustic pulse generator, an impedance matching layer, and a thermal management system. The thermal management system is mounted to the matching layer to transfer heat from the matching layer, and is formed of a high thermal conductivity material relative to the matching layer. The thermal management system is arranged along the matching layer such that substantial heat is transferred to the environment from the thermal management system without excessive temperature increase at the pulse generator.

Abstract: A flow conditioner includes a body composed of an array of vanes generally parallel to the direction of fluid flow. The vanes create a plurality of chambers to effectively reduce large scale vortices in the flow. The vanes have surfaces with perforations to allow pressure regulation between chambers to effectively reduce asymmetric flow and reduce drag. Additional preferred features include an acoustic choke created by a reduction in cross-sectional flow area at the entrance and the exit of the flow conditioner with circular plates. The plates have rough edges to increase production of micro-vortices.

Abstract: A sample bag for collecting a mixture of gasses for analysis is made of a modified polymer consisting essentially of tetrafluoroethylene (TFE) and at most about 2.0 percent perfluoropropylvinylether (PPVE).

Abstract: A mixing system with proportional dilution gas sampling, and associated proportional dilution gas sampling methods are provided. The mixing system includes a mixing portion, a gaseous inlet, a dilution inlet, and a mixture outlet. A flow meter in flow communication with the dilution inlet has an output indicative of the dilution gas flow rate. A dilution sample line in flow communication with the dilution inlet collects samples of the dilution gas. A dilution sample flow controller along the dilution sample line is applicable to vary the dilution sample flow rate through the dilution sample line. Control logic receives the flow meter output, processes the flow meter output, and operates the dilution sample flow controller to vary the dilution sample flow rate. The dilution sample flow rate is varied in response to variations in the dilution gas flow rate such that the dilution sample flow rate tracks a value which is substantially proportional to the dilution gas flow rate.

Abstract: A sample of gaseous constituents, to be used in e.g. emissions testing, is collected within an inner bag 86 having a wall 92 that allows limited diffusion of at least one of the gaseous constituents therethrough. A control gas is then collected into an outer bag 82 that defines an auxiliary chamber 94 between the wall and the outside environment. The control gas controls the rate of diffusion of the at least one constituent through the wall and into the outside environment.

Abstract: A sample bag for collecting a sample of gaseous constituents defines a sample chamber with a wall that allows a constituent to diffuse therethrough, and defines an auxiliary chamber on the other side of the wall to receive the diffusing constituent. Advantageously, a control gas may be provided in the auxiliary chamber to control the rate of net diffusion across the wall of the sample chamber. The control gas may be the same as the sample gas.

Abstract: A sample bag for collecting a mixture of gasses for analysis is made of a modified polymer consisting essentially of tetrafluoroethylene (TFE) and at most about 2.0 percent perfluoropropylvinylether (PPVE).