Abstract: A zeta potential measurement system comprising: a cell having a cell wall and bottom for holding suspended particles; an optical measurement probe having a probe tip comprising a transparent and conducting thin film coating which prevents ionic current from accumulating charge on the probe tip, and wherein the optical measurement probe is inserted through the cell wall such that the probe tip is in fluid communication with the sample; a counter electrode inserted through the cell wall opposite to the optical measurement probe; a laser source which is disposed so as to deliver light to the optical measurement probe via an optical directional coupler and optical waveguide; wherein the optical measurement probe focuses the light onto a front surface of the probe tip, such that the light reflected from the front surface of the optical measurement probe and light backscattered from particles in the sample are collected by the probe tip, and thereafter focused to a optical waveguide and delivered through the couple

Abstract: A zeta potential measurement system comprising: a cell having a cell wall and bottom for holding suspended particles; an optical measurement probe having a probe tip comprising a transparent and conducting thin film coating which prevents ionic current from accumulating charge on the probe tip, and wherein the optical measurement probe is inserted through the cell wall such that the probe tip is in fluid communication with the sample; a counter electrode inserted through the cell wall opposite to the optical measurement probe; a laser source which is disposed so as to deliver light to the optical measurement probe via an optical directional coupler and optical waveguide; wherein the optical measurement probe focuses the light onto a front surface of the probe tip, such that the light reflected from the front surface of the optical measurement probe and light backscattered from particles in the sample are collected by the probe tip, and thereafter focused to a optical waveguide and delivered through the couple

Abstract: An adjustable focusing assembly for use with an optical probe includes a focusing element having a first and a second end mounted within a holder member. The holder member is secured to the optical probe with the focusing element optically coupled to the light images projecting from the light probe. A window having an inner and an outer surface is mounted on a body member with the window inner surface in a facing and spaced relationship to the focusing element second end. The body member further includes a cowled portion extending from the periphery of the body member on a side opposite the window, arranged to engage surfaces on the periphery of the holder member, thereby defining a cavity between the focusing element second end and the window inner surface. The body member is adjusted, increasing or alternatively decreasing the cavity until the light images from the focusing element second end are focused on the window outer surface.

Abstract: An optical detection system and method is disclosed comprising a first light guide for conveying light energy from a light source to a first light guide face end that is immersed in a dispersant medium. A first portion of the light energy exits the face end to irradiate particles contained in the dispersant medium and a second portion of the light energy is reflected by the face end back into the first light guide. A frequency transducer mounted to the first light guide receives at least one specific frequency from a range of frequencies generated by a frequency oscillator and oscillates the first light guide face end at the applied specific frequency. The transducer oscillations are further coupled into the dispersant medium, causing the dispersant medium and the particles contained therein to oscillate at the oscillation frequency of the first light guide face end.

Abstract: A method for producing measurements of specific key characteristic parameters of small particles suspended within a scattering medium includes the step of directing a beam of light into the scattering medium, then detecting the Doppler-shifted components of light scattered by the movement of the suspended particles and unscattered light from the source and generating a first signal representative of the power spectral density of the Doppler-shifted components and unscattered light. The first signal is next applied to a plurality of bandpass filters to generate a plurality of second signals, the magnitude of which are representative of the power spectral density integrated over the bandpass. The first signal is also applied to a low pass filter that generates a third signal, used in deriving the concentration of the particles in the scattering medium.

Abstract: A fiber optic hygrometer apparatus and method for sensing and measuring the dew point of an atmosphere is disclosed that includes a controller for controlling the operation of the apparatus and a first optical fiber for transmitting light energy from a source of light energy to an optical core extending into the atmosphere being monitored. The optical core includes an end that is prepared as a reflecting surface, allowing the light energy reaching the optical core to be internally reflected back toward the source. A second optical fiber captures the light energy internally reflected from the optical core and conveys the captured light energy to a light energy detector. The light energy detector is arranged to output signals to the controller representing the magnitude of the light energy captured. A cooling device and a temperature-sensing device operationally connected to the controller are attached to the optical core.

Abstract: A multiple pathlength sensor is disclosed that is installed substantially within a process stream containing particles at high concentrations. The sensor includes a transparent surface for receiving the first and the second light energy emissions projected by first and second light delivery arrangements. The first and second light energy emissions penetrate the transparent surface and enter the sensor in a first directional path. A first light deflecting surface modifies the first and second light energy emissions to travel into a second directional path through the sensor. A first passage exposed to the process stream is sized to receive particles of a first predetermined size range. The first light energy emission in the second directional path is projected through the first passage to irradiate the particle ensemble therein. A second passage exposed to the process stream is sized to receive particles of a second predetermined size range.

Abstract: A system is disclosed for determining the distribution of the size of small particles contained in a sampled portion of a process stream containing particles at high concentrations. The system includes a light delivery arrangement that anamorphically modifies light energy received from a light source and projects the anamorphically modified light energy to an optical element contained in a sample cell. The optical element includes a passage that is arranged to receive therein particles of a predetermined size from the sampled portion of the process stream flowing in the sample cell. The anamorphically modified light energy is transmitted through the optical element and is focused within the passage to irradiate the particle ensemble therein. A light collection arrangement collects the light energy escaping from the optical element and focuses the light energy collected onto a detector array.

Abstract: A detector used in a measurement system that determines the size distribution of particles contained in a dispersant medium is disclosed that includes means for exciting the dispersant medium at an ultrasonic frequency to cause particles contained in the dispersant medium to oscillate at the applied ultrasonic frequency. The detector of the present invention further includes a light source for producing light energy in a specific frequency range, a first light guide for conveying the light energy from the light source to the dispersant medium, a second light guide for capturing and conveying the light energy scattered by the particles in oscillation and a third light guide for conveying light energy from said light source to the second light guide to produce heterodyned light energy. A light energy detection device optically connected to the second light guide receives the heterodyned light energy and produces signals representative of the heterodyned light energy detected.

Abstract: An optical sensor for detecting the dew point of an atmosphere is disclosed for use with an optical measurement system. The optical measurement system includes a source of light energy, a light detector, and a light energy conduction arrangement for directing light energy from the source of light energy to the optical sensor. The light energy conduction arrangement also returns light energy from the optical sensor to the light detector. The optical sensor of the present invention includes a substrate located within the atmosphere and a first waveguide located on a surface of the substrate. The first waveguide includes a first end optically connected to the light energy conduction arrangement arranged to receive thereat light energy from the source of light energy and to direct thereat light energy to the light detector. A second waveguide is located on the substrate first surface parallel to and in a spaced relationship to the first waveguide.

Abstract: A low power apparatus for measuring various process parameters and/or physical properties of a fluid or gas medium by measuring the change of a wave signal or time dependent signal as it traverses the fluid or gas medium, the apparatus comprising: at least one transmission transducer for providing a transmitted wave or time dependent signal for injection into the fluid or gas medium; at least one reception transducer, displaced from the transmission transducer for receiving a received wave or time dependent signal from the fluid or gas medium; and an analog signal processor, coupled to the reception transducer, for processing of the received wave or time dependent signal such that a short interval of the processed received wave or time dependent signal is extracted.

Abstract: A method (and corresponding apparatus) for determining the size distribution of small particles within a dispersing medium utilizing a particle analyzer that measures the angle of scattered light, including the step of sequentially irradiating the particles within the dispersing medium with each of a plurality of light sources positioned at different angles. The scattered light developed by sequentially irradiating the particles is focused, utilizing at least one collector lens, onto a detector array associated with each such lens and the angular distribution of scattered light associated with each of the plurality of light sources is sequentially measured utilizing each detector array associated with a given lens. Finally, the measured angular distributions of scattered light associated with the plurality of light sources, is translated into a size distribution for the particle ensemble contained in the dispersing medium, using well known inversion techniques, such as deconvolution.

Abstract: A Doppler velocimeter for measuring the doppler frequency shift of light scattered from particles suspended in a medium. The velocimeter includes a light source and an integrated optical waveguide having a first optical waveguide path for receiving an incident beam of light from the light source at one end. The first waveguide path further guides the incident beam to a second end which is located in the medium adjacent the particles. A second optical waveguide path is optically coupled to the first waveguide path for receiving the scattered light from the particles as well as the non-scattered light and guiding both to the other end thereof. A detector receives the scattered and non-scattered light from the second waveguide and converts it to an electrical signal indicative of the doppler frequency shift.

Abstract: A method of measuring the size distribution of moving particles within a scattering medium includes a step of directing a beam of light into the scattering medium. The frequency of the scattered light is compared to nonscattered light emitted from the scattering medium and results in the generation of a first signal having a magnitude which is indicative of the difference in frequency between the scattered light and the nonscattered light. A second signal is generated having a magnitude which varies with frequency on a linear scale. The frequency scale of the second signal is then translated to a logarithmic scale. Finally, the translated second signal is deconvolved to determine the size and distribution of moving particles within the scattering medium.

Abstract: A photoelastic transducer is constructed with a photoelastic element receiving a 45.degree. polarized light beam with a wave plate providing a 90.degree. phase displacement in its orthogonal components. The element has reflective surface coatings to produce multiple internal reflections so as to lengthen the optical path, and increase the sensitivity of the unit. Analysis of the orthogonal outputs can be according to the difference divided by the sum with one of the outputs being multiplied by the ratio of the D.C. component of the other output to its D.C. component, for the purpose of compensating for changes in tramsmission of the two signals.