A transmissometer and method for determining a transmissivity of an atmosphere within a chamber. A chamber contains the atmosphere. A light source generates a test beam and a light detector detects the test beam. A periscope is movable between a first position which allows the test beam to pass through the atmosphere in the chamber and into the light detector and a second position in which the test beam is deflected to pass into the light detector without passing through the atmosphere in the chamber. A processor determines the transmissivity of the atmosphere from a transmissivity measurement for the test beam obtained by the light detector when the periscope is in the first position and a transfer standard obtained at the light detector when the periscope is in the second position.

A gas sensor has a light detector, a gas-tight support structure enclosing the light detector, a window positioned in said support structure, and a light source mounted to the support structure. A sample area is positioned in the support structure to receive a gas to be tested. The light source is aligned with the window, sample area, and the light detector to pass light from the light source through the gas in the sample area to the light detector. The sensor can be provided in a breadth sampling apparatus that has deflects gas to a bypass route so that only a portion of gas reaches the sensor.

A point of use analyte detection and quantification system for aquatic applications is provided. Related methods are also provided.

A gas sensor has a light detector, a gas-tight support structure enclosing the light detector, a window positioned in said support structure, and a light source mounted to the support structure. A sample area is positioned in the support structure to receive a gas to be tested. The light source is aligned with the window, sample area, and the light detector to pass light from the light source through the gas in the sample area to the light detector. The sensor can be provided in a breadth sampling apparatus that has deflects gas to a bypass route so that only a portion of gas reaches the sensor.

A monitoring system for monitoring a process includes a housing with a viewing panel. The viewing panel includes a view port. An emitter generates light and illuminates an observation zone of the process. A detector is disposed within the housing and is configured to detect light entering the housing through the view port and create a plurality of images of the process in the observation zone. A thermal regulation system is configured to generate heat in the vicinity of the viewing panel of the housing so as to increase the temperature of at least the view port above ambient temperature.

A method and apparatus are described for measuring the concentration of a gas with an absorption band in the ultraviolet range. The device includes an absorption chamber containing a gas, a light source, a selected optical bandpass filter, and ultraviolet photodetectors. The gas concentration is measured by the ratio of a transmitted intensity to an incident intensity with the Beer-Lambert Law relation. A second light source may be used for a compensation signal. A second method periodically changes the absorption coefficient by inserting a transparent material in the absorption path to measure the optical compensation signal. A third method periodically shortens the optical absorption path by moving the active detector closer to the light source to measure the optical compensation signal. The fourth method uses an optical element to deflect the optical beam to create a shorter absorption path as a reference for the incident signal using one detector.

A laser absorption spectroscopy exhaust gas sensor includes an optical cell with porous walls having pores with a mean diameter in the range of 0.1 nm to 1 mm; gold mirrors within the optical cell positioned to support a multi-pass optical path within the optical cell; an active heating element adapted to heat the optical cell to prevent condensation; a laser adapted to generate a laser beam; an optical detector adapted to detect a returning laser beam; and a processor for controlling the laser and the active heating element and for analyzing signals from the optical detector to identify a gas in the optical cell.

An optical measuring device that measures one or more parameters indicating a state of a measured liquid, includes: a light source that irradiates light to the measured liquid; a light receiver that detects a measured light based on the light irradiated to the measured liquid; an optical component that is disposed on an optical path between the light source and the light receiver; and a heat source on the optical component and that has optical transparency and electrical conductivity.

A point of use analyte detection and quantification system for agricultural applications is provided. Related methods are also provided.

A point of use analyte detection and quantification system for agricultural applications is provided. Related methods are also provided.