Abstract: A multichannel fluorosensor includes an optical module and an electronic module combined in a watertight housing with an underwater connector. The fluorosensor has an integral calibrator for periodical sensitivity validation of the fluorosensor. The optical module has one or several excitation channels and one or several emission channels that use a mutual focusing system. To increase efficiency, the excitation and emission channels each have a micro-collimator made with one or more ball lenses. Each excitation channel has a light emitting diode and an optical filter. Each emission channel has a photodiode with a preamplifier and an optical filter. The electronic module connects directly to the optical module and includes a lock-in amplifier, a power supply and a controller with an A/D converter and a connector. The calibrator provides a response proportional to the excitation intensity, and matches with spectral parameter of fluorescence for the analyzed fluorescent substance.

Abstract: A turbidity measuring system is provided with a chamber and a sensor having a watertight housing, a light source, a first light focusing device for focusing a light emitted from the light source and passing therethough into a sample liquid, a second light focusing device for collecting at least one scattered light resulted form the focused light when passing the sample liquid, a photodiode for receiving the collected light thereby generating electronic signals, and an electronic board for processing the electronic signals. In particular, the watertight housing has a tilted bottom, the light detector includes at least two photodiodes for detecting separated turbidity measuring ranges, or an insert is placed at the bottom of the chamber having first and second insert channels each of whose axis pointing toward an axis of one of the cylindrically-shaped channels in the watertight housing in order to trap light.

Abstract: A portable multi-channel device for optically testing of a liquid sample includes a controller; and a sample holder with a cylindrical sample compartment and at least two optical channels respectively for measuring turbidity of the sample liquid and for measuring one other optical property of the sample liquid. Each of the optical channels including: a light source placed at one end of the channel, a main detector placed across the sample compartment from the light source, a reference detector for measuring an intensity of light emitted by the light source, and an excitation focusing optic for directing a light emitted by the light source through the sample compartment towards the main detector. Signals from the reference detector of the channel, the main detector of the channel, and another main detector of another channel perpendicular to the channel are processed by the controller to evaluate the turbidity of the liquid sample.

Abstract: A multichannel fluorosensor includes an optical module and an electronic module combined in a watertight housing with an underwater connector. The fluorosensor has an integral calibrator for periodical sensitivity validation of the fluorosensor. The optical module has one or several excitation channels and one or several emission channels that use a mutual focusing system. To increase efficiency, the excitation and emission channels each have a micro-collimator made with one or more ball lenses. Each excitation channel has a light emitting diode and an optical filter. Each emission channel has a photodiode with a preamplifier and an optical filter. The electronic module connects directly to the optical module and includes a lock-in amplifier, a power supply and a controller with an A/D converter and a connector. The calibrator provides a response proportional to the excitation intensity, and matches with spectral parameter of fluorescence for the analyzed fluorescent substance.

Abstract: The invention provides a radiation sensor including a housing, an attenuator with at least one cavity for attenuating optical radiation, and a detector, as well as an optical attenuator including an attenuator body, an entrance with one multi-stage input opening or plural input openings, and means for transferring radiation inside of the attenuator body and then to a detector. The invention further provides methods for using the radiation sensor or the optical attenuator.

Abstract: A turbidity measuring system is provided with a chamber and a sensor having a watertight housing, a light source, a first light focusing device for focusing a light emitted from the light source and passing therethough into a sample liquid, a second light focusing device for collecting at least one scattered light resulted form the focused light when passing the sample liquid, a photodiode for receiving the collected light thereby generating electronic signals, and an electronic board for processing the electronic signals. In particular, the watertight housing has a tilted bottom, the light detector includes at least two photodiodes for detecting separated turbidity measuring ranges, or an insert is placed at the bottom of the chamber having first and second insert channels each of whose axis pointing toward an axis of one of the cylindrically-shaped channels in the watertight housing in order to trap light.

Abstract: An automated system for periodically sampling water bodies, such as lakes, and delivering the test results to a remote computer using a communication system. In particular, the system has a variable buoyancy profiler with a dynamic buoyancy compensator responding approximately linear to a water pressure created by an external water body so as to actively or passively interact with an external force or pressure thereby moving the profiler to a target depth.

Abstract: A small size turbidity sensor for underwater in-situ measurements in the wide range of turbidity values is disclosed that may be integrated into a housing with other underwater sensors. The turbidity sensor incorporates micro focusing devices and light stop that gives no divergence excitation beam with convergence less than 1.5 degrees and the measuring angle between the optical axis of the incident radiation and mat of the diffused radiation 90 ±2.5 degrees. Another embodiment includes internal and external optical calibrators that allows the sensor to work longer without human intervention.

Abstract: The invention provides a radiation sensor including a housing, an attenuator with at least one cavity for attenuating optical radiation, and a detector, as well as an optical attenuator including an attenuator body an entrance with one multi-stage input opening or plural input openings, and means for transferring radiation inside of the attenuator body and then to an detector. The invention further provides methods for using the radiation sensor or the optical attenuator.

Abstract: A turbidity sensor for underwater measurements is provided with a watertight housing, a light emitting diode, a first light focusing device for focusing a light emitted from the diode and passing the focused light into to-be-measured water, a second light focusing device for collecting at least one scattered light resulted form the focused light when passing the water, a photodiode for receiving the collected light thereby generating electronic signals, and an electronic board for processing the electronic signals.

Abstract: An automated system for periodically sampling water bodies, such as lakes, and delivering the test results to a remote computer using a communication system. In particular, the system has a variable buoyancy profiler with a dynamic buoyancy compensator responding approximately linear to a water pressure created by an external water body so as to actively or passively interact with an external force or pressure thereby moving the profiler to a target depth.

Abstract: A multichannel fluorosensor includes an optical module and an electronic module combined in a watertight housing with an underwater connector. The fluorosensor has an integral calibrator for periodical sensitivity validation of the fluorosensor. The optical module has one or several excitation channels and one or several emission channels that use a mutual focusing system. To increase efficiency, the excitation and emission channels each have a micro-collimator made with one or more ball lenses. Each excitation channel has a light emitting diode and an optical filter. Each emission channel has a photodiode with a preamplifier and an optical filter. The electronic module connects directly to the optical module and includes a lock-in amplifier, a power supply and a controller with an A/D converter and a connector. The calibrator provides a response proportional to the excitation intensity, and matches with spectral parameter of fluorescence for the analyzed fluorescent substance.

Abstract: A sensor array includes a plurality of sensors connected to two or more groups of wires such that individual sensors can be addressed. No two sensors are connected to the same two wires. The groups of wires are connected to multiplexers or the like to address particular wires connecting a unique sensor. Dramatically improved accuracy is obtained by connecting rectifiers in series with the sensors to significantly reduce reverse current through a sensor that can lead to significant errors.

Abstract: An infrared spectrometer for the determination of isotopic ratios of gaseous compounds includes a broad-band infrared light source, a spectral selector, a sample compartment, an infrared detector, and a processor. The spectral selector selectively transmits a wavelength window of infrared light covering a range of wavelengths in which the wavelength window can be selected alternatively to overlap with a wavelength range primarily absorbed by a compound with a first isotope or by the compound with a second isotope. The sample compartment holds a gas sample and includes a gas inlet and a gas outlet. The infrared spectrometer can be used to detect isotopic ratios of carbon dioxide, where enhancement of 13CO2 can indicate metabolic activity of an infection, for example by H. pylori, or of specific enzymes. Preferred embodiments use a particular multipass optical cell that includes a field mirror and a multi-segment objective mirror.