A series of optical spectral sensors is based on a combination of solid-state sources and detectors housed within an integrated package that includes the interfacing optics and acquisition and processing electronics. Spectral selectivity is provided by the solid-state source(s) thereby eliminating the need for expensive spectral selection components. The spectral response covers the range from the visible (400 nm) to the mid-infrared (25,000 nm/25.0 µm), as defined by the availability of suitable low-cost solid-state source devices. A refractive optical system (44) is employed, primarily in an internal reflection mode, allowing a selection of sample handling tools, including internal reflectance and transmittance. A secondary channel allowing for light scattering or fluorescence methods is an option. The targeted applications of the sensors are for lubricants and functional fluids in the heavy equipment, automotive and transportation industries. A source reference channel is included to provide measurement stability and temperature compensation.

Low-cost on-line and in-line spectral sensors based on solid-state source and detectors combinations for monitoring lubricants and functional fluids

An integrated spectral sensing engine featuring energy sources and detectors within a single package includes sample interfacing optics and acquisition and processing electronics. The miniaturized sensor is optimized for specific laboratory and field-based measurements by integration into a handheld format. Design and fabrication components support high volume manufacturing. Spectral selectivity is provided by either continuous variable optical filters or filter matrix devices. The sensor's response covers the range from 200 nm to 25 μm based on various solid-state detectors. The wavelength range can be extended by the use of filter-matrix devices. Measurement modes include transmittance/absorbance, turbidity (light scattering) and fluorescence (emission). On board data processing includes raw data acquisition, data massaging and the output of computed results. Sensor applications include water and environmental, food and beverage, chemical and petroleum, and medical analyses. These can be expanded into various field and consumer-based applications.

Integrated sensing module for handheld spectral measurements

Method and apparatus for real time particulate monitoring in a fluid utilizing a laser directed at the suspended particle-containing fluid, two-dimensional multiple sensor radiation detector means receiving back-scattered radiation from the particles generating electrical pulse signals representative of individual particle size and number, and means determining particle size distribution as a function of signal pulse height.

Method and apparatus for particulate monitoring

An integrated spectral sensing engine (Fig. 1) featuring energy sources and detectors within a single package includes sample interfacing optics and acquisition and processing electronics (Fig. 4, Fig. 5). The miniaturized sensor is optimized for specific laboratory and field-based measurements by integration into a handheld format (Fig. 12). Design and fabrication components support high volume manufacturing. Spectral selectivity is provided by either continuous variable optical filters or filter matrix devices. The sensor's response covers the range from 200 nm to 25 mm based on various solid-state detectors. The wavelength range can be extended by the use of filter-matrix devices. Measurement modes include transmittance/absorbance, turbidity (light scattering) and fluorescence (emission). On board data processing includes raw data acquisition, data massaging and the output of computed results. Sensor applications include water and environmental, food and beverage, chemical and petroleum, and medical analyses. These can be expanded into various field and consumer-based applications.

An integrated sensing system approach for handheld spectral measurements

An underwater light scattering sensor includes a light source, light stop and a light detector mounted on a planar support capable of measuring nearly all suspended particle concentrations found in natural waters, 1 μg/l to 3 g/l. The sensor is designed to measure light scattered at nearly all angles, which includes forward scattering, back scattering, and multiple scattering, from suspended particles in water through a very short light path length. The small and simple design of the sensor allows it to be produced at low cost, permitting its use in both expendable and non-expendable applications for the detection or measurement of suspended particulate concentrations in water. The magnitude of the scattered light measured by the sensor is proportional to the suspended particle concentration in water, provided the nature of the particles does not change.

Underwater light scattering sensor

A turbidimeter having a probe mounted in a single opening in a fluid flow line which has a smooth uniform face in contact with the flowing fluid, a collimated incident light source and a photosensitive cell positioned to receive back scatter light

Shea James J

Papers

Turbidimeter utilizing back scatter