The air condition measurement apparatus according to various embodiments of the present invention comprises: a housing comprising a first space and a second space therein; a light-emitting unit which is positioned inside the housing, comprises a first lens, and radiates light to air flowing into the housing; a light-receiving unit which is positioned inside the housing, comprises a second lens, and receives reflected light formed from the reflection of the radiated light, radiated from the light-emitting unit, by foreign substances included in the air; a blocking member which transmits the radiated light or the reflected light and separates the first space, in which the light-emitting unit or the light-receiving unit is disposed, from the second space; and a control unit, wherein the control unit may be configured to measure the condition of air on the basis of a signal corresponding to the reflected light received by the light-receiving unit. Other various embodiments may be possible.

A contamination sensor for an optical sensor observation window includes a source, two prisms, a detector, and a controller. The source can emit a collimated light beam at an incident angle that is greater than a critical angle of an interface between a fluid and the window. The window has a refractive index greater than the refractive index of the fluid. The prisms can direct the collimated light beam within the window such that the collimated light beam reflects within a contamination detection zone of the window. The detector can receive the collimated light beam. The controller can communicate with the source and detector. The controller can calculate an emission/detection ratio defined by a difference between an amount of light emitted by the source and an amount of light that passes from the source to the detector by a total internal reflectance of the window.

A contamination sensor for an optical sensor observation window includes a source, two prisms, a detector, and a controller. The source can emit a collimated light beam at an incident angle that is greater than a critical angle of an interface between a fluid and the window. The window has a refractive index greater than the refractive index of the fluid. The prisms can direct the collimated light beam within the window such that the collimated light beam reflects within a contamination detection zone of the window. The detector can receive the collimated light beam. The controller can communicate with the source and detector. The controller can calculate an emission/detection ratio defined by a difference between an amount of light emitted by the source and an amount of light that passes from the source to the detector by a total internal reflectance of the window.

An example article may include an optical filter and a multilayer stack adjacent the optical filter. The multilayer stack may include a plurality of layers. Each respective layer of the plurality layers may define a respective window edge of a plurality of window edges. The plurality of window edges may define an optical window configured to transmit light through the optical filter. At least a first respective window edge of the plurality of window edges may be stepped relative to at least a second respective window edge of the plurality of window edges.

An example article may include an optical filter and a multilayer stack adjacent the optical filter. The multilayer stack may include a plurality of layers. Each respective layer of the plurality layers may define a respective window edge of a plurality of window edges. The plurality of window edges may define an optical window configured to transmit light through the optical filter. At least a first respective window edge of the plurality of window edges may be stepped relative to at least a second respective window edge of the plurality of window edges.

In order to provide an absorption analyzer capable of directly measuring an analysis target gas flowing into or produced in a vessel such as a chamber and preventing a measurement error due to moisture condensation, the absorption analyzer is adapted to include: a light emission module that is attached covering a first opening of the vessel into which the analysis target gas flows or in which the analysis target gas is produced and emits light into the vessel; and a light detection module that detects the light emitted from the light emission module and passing through the vessel. In addition, the light emission module is adapted to include: a base flange that is attached around the first opening on an outer surface of the vessel; a window material whose outer surface is tilted at a predetermined angle; a seal member; and a pressing body.

A cuvette for arrangement in an optical measuring device includes a receiving chamber for a measuring medium having an inlet. The receiving chamber is delimited at least in some regions by two opposing plane-parallel side surfaces. Two opposing metallic electrodes are arranged in the receiving chamber on the opposing side surfaces.

Systems and methods are disclosed for identifying a dirty camera in a monocular camera comprising n cameras. For each of one or more cycles, a dirty counter variable for each of the n cameras is set to 0. For each of the n cameras, an image is captured from the camera and an image metric is determined for the image, e.g. brightness and/or contrast. If the image metric is 10% greater, or 10% less, than the image metric for any of the other n−1 cameras in the monocular camera, then that camera is determined to be dirty and a corrective action is taken, such as sending an alarm to an occupant the vehicle or initiating a cleaning operation. If the dirty condition persists for a camera that has been cleaned within a threshold period of time (i.e., recently), then an alarm is sent to an operator of the vehicle.

An object of the present claimed invention is to improve cell cooling performance, keep a temperature of a dispersion medium constant, and improve measurement accuracy. The particle size distribution measuring device of this invention comprises a cell holding body 31 that holds a cell 2 housing a measurement sample and that is rotated by a motor 322, a case (C) having a housing space (S) for rotatably housing the cell holding body 31, and a cooling mechanism 8 for cooling the cell 2. The cooling mechanism 8 comprises a cooler 81, and a supply channel 82 that supplies a gas that has been cooled by the cooler 81 to the housing space (S).

An instrument incorporating a refractometer for measuring parameters of a fluid such as a metalworking fluid, avoids impairment of measurement accuracy due to contact of entrained air and oil with a refractometer window by temporarily interrupting the flow of the fluid through a refractometer chamber and orienting the window so that air and oil will readily separate from the window during the interruption of flow. Continued flow of metalworking flow while refractive index measurements are taken can be achieved by the use of by-pass valving arrangements.