Provided is a portable biosensor that includes a sample filter cartridge, a filter collector, an optical sphere, an electromagnetic radiation emitter, a photo-detector, a processor, a signal display, a vacuum pump, and a power supply. The sample filter cartridge selectively removes small molecules to minimize spectral interference in the detection signal. The sample is concentrated onto the filter collector and subjected to illumination by the electromagnetic radiation emitter, producing Raman-scattering. The optical sphere collects and distributes the Raman-scattering shifts, which then pass through a spectral filter to produce spectral filtered scattering, which is then reflected by the concave holographic flat-field grating onto the photo-detector. The data is displayed graphically to provide the Raman-scattering shift data. The data is compared with a database for sample identification. The device is contained within a housing that is small enough to be easily transported for field use.

A gas measuring device includes: a gas rectification unit configured to rectify gas to control traveling directions and traveling speeds of gas molecules based on molecular weights of the gas molecules; and a gas sensor configured to absorb the gas molecules of the gas rectified by the gas rectification unit, and to detect absorption positions and absorption amounts.

To uniformly dilute particulate matter contained in a sample gas, a diluter includes an inflow portion, a mixing portion, a discharge portion, a connection portion, and an introduction portion. The inflow portion allows a sample gas to flow in. The mixing portion has an inner diameter larger than that of the inflow portion, and mixes the sample gas with a dilution gas to generate a diluted sample gas. The discharge portion discharges the diluted sample gas. The connection portion has a first tapered part whose inner diameter increases from a side connected to the inflow portion toward a side connected to the mixing portion. The introduction portion introduces the dilution gas into an internal space from a position downstream of the connection between the first tapered part and the inflow portion.

The system includes a dust collector, a pressure controller, a dryer, a gas heat-insulation device, a gas pool, a gas detector, an optical monitor and a computer sequentially connected. The dust collector is used to filter solid particles in a gas. The pressure controller is used to control a flow rate of the gas. The dryer is used to control a humidity of the gas. The gas heat-insulation device is used to control a temperature of the gas. The gas pool is used to carry the gas. The laser is used to irradiate the gas in the gas pool to generate a Raman scattering light. The gas detector is used to collect the Raman scattering light. The optical monitor is used to adjust and amplify a light signal of the Raman scattering light. The computer is used to output a Raman spectrum and a composition and content of a tar.

In order to allow an analyzer to be calibrated or a sampling channel to be purged without removing a sampling probe from a sampling location, provided are a sampling channel through which an exhaust gas from an internal combustion engine flows, an analyzer that is connected to the sampling channel and analyzes the exhaust gas, a diluter provided upstream of the analyzer in the sampling channel, a recirculated channel that branches from a branch point set between the analyzer and the diluter in the sampling channel and joins the diluter, a pump that is provided in the recirculated channel and guides part of the exhaust gas from the branch point to the diluter, an additional channel that is connected to the recirculated channel or the sampling channel and through which a calibration gas or a purge gas flows, and an opening and closing mechanism provided in the additional channel.

A gas sampling apparatus including a housing having a housing wall and a housing opening. The gas sampling apparatus includes a sample system for extracting the gaseous sample, including a sample pipe having an opening enclosed by the housing wall and in fluid communication with the gaseous environment and filter means including a filter for filtering solid particles from the gaseous sample. The filter is enclosed by the housing wall and arranged at the opening. The gas sampling apparatus includes a central purge system to remove aggregates of solid particles deposited on one or more housing surfaces by a gaseous medium, wherein the central purge system includes a purge pipe including an outlet opening directed towards the housing opening and enclosed by the housing wall, wherein the sample system is arranged externally to the central purge system so that the sample pipe is separate from the purge pipe.