A device for scattered light measurement of particles in a gas, comprising a light source, a beam splitter which splits a light beam emitted by the light source into a measuring beam and a reference beam, a light receiving device arranged at a distance from the beam splitter, which comprises at least one lens arranged in the reference beam with an optical axis aligned at an acute angle to the measuring beam, a first light receiver on the side of the lens facing away from the beam splitter, for receiving the scattered light imaged by the latter from a measurement volume in a gas-bearing region between the beam splitter and the lens, and a second light receiver on the side of the lens facing away from the beam splitter for receiving the reference beam imaged by the latter.

A method is provided for detecting primary gas flows (18) in flow chambers (10). The primary gas (18) flowing in a flow chamber (10) is locally seeded with a seed substance and the movement of the seed substance, representative of the flow of the primary gas (18), is detected by imaging by an image detector (28) and an imaging optics (30) arranged in front of said image detector (28). A gas mixture (34) that moves along with the primary gas (18) without relative motion and that has a refractive index distinguishable from that of the primary gas (18) is used as the seed substance, and imaging detection is carried out by a background schlieren measurement method.

The optical cell of an elongated shape has an inner space into which gas is introduced and includes: a cell main body forming the inner space; a manifold member being separably connected to an outer surface of the cell main body extending in a longitudinal direction; and a heating mechanism heating the manifold member, in which the cell main body has a through hole penetrating from the outer surface into the inner space, and the manifold member has a gas introduction path extending along the longitudinal direction and guiding the gas, which has been taken in from the outside, from one side to another side in the longitudinal direction and then guiding the gas to the inner space through the through hole.

A particle concentration measurement system includes a first window and a second window separated by a sensing volume. The system also includes one or more supports to provide structural support for the first window at a first end and for the second window at a second end, opposite the first end, of each of the one or more supports. The sensing volume is defined by the one or more supports and the first window and the second window is open to an environment of the particle concentration measurement system adjacent to the one or more supports such that particle-laden gas from the environment that includes particles mixed with other materials enters the sensing volume. A first compressed gas orifice directs compressed gas onto the first window to clean the first window and a second compressed gas orifice directs the compressed gas onto the second window to clean the second window.

Provided is a flocculation state monitoring sensor with which blockage of an ejecting part which ejects a gas towards a light emitting part and a light receiving part can be prevented, and which performs stable monitoring. A flocculation state monitoring sensor comprising: a light emitting part which irradiates laser light towards a measuring region which measures a flocculation state; and a light receiving part which receives light scattered along a direction which intersects with a direction along an optical axis of said light emitting part, wherein the light emitting part and the light receiving part are cleaned by air being ejected from nozzles theretowards. A small amount of air is provided to the nozzles between cleaning periods to purge floc, etc.

Various embodiments include systems and apparatuses for reducing contamination levels within optical chambers of particle-detection instruments. In one embodiment, an apparatus to reduce contamination within an optical chamber of a particle-detection instrument is described. The apparatus includes a plenum chamber to at least partially surround an aerosol-focusing nozzle of the particle-detection instrument and accept a filtered gas flow. A curtain-flow concentrating nozzle is coupled to the plenum chamber to produce a curtain flow into the optical chamber to substantially surround an aerosol flow. Other methods and systems are disclosed.

An enclosure surrounding the optical component can be connected with a vapor source. The vapor source can provide a vapor to the enclosure with a vapor level from 500 ppm to 15000 ppm. The concentration of vapor in the enclosure can increase the lifespan of the optical component in the enclosure.

A tool arrangement is provided for accommodating portions of an optical tool in a park position, having an optical tool and having a housing with an opening suitable for accommodating portions of the optical tool in a housing interior, with a housing discharge connected to the housing in a fluid-conducting manner, and with a sealing sleeve arranged at the opening of the housing, wherein the sealing sleeve has a fluid-carrying line for adapting a variable fill volume of the sealing sleeve. In addition, a method is provided for accommodating portions of an optical tool in a park position.

An optical sensor for sensing combustion products avoids fouling and damage to optical components by using a “windowless” design in which an air curtain through an orifice provides a constantly refreshing transparent shield protecting the optical components from corrosive combustion gases and resisting the accumulation of particulates that might otherwise foul a static window.

A sealing arrangement and method of a measuring device are disclosed, the measuring device having one or more measuring elements that have a surface in contact with a fluid being measured, a fluid chamber for the fluid being measured, and a seal to seal the joint between the fluid chamber and the measuring element. Flow channels have been formed in the measuring device to lead the rinsing fluid in contact with the seal.