Abstract:
An infrared sensor assembly for sensing infrared radiation from an object is disclosed. The infrared sensor assembly comprises a sensor array comprising a plurality of sensing elements, provided on or embedded in a substrate extending in a substrate plane. The sensor array comprises at least two infrared sensing elements, each infrared sensing element having a radiation responsive element providing a proportionate electrical signal in response to infrared radiation incident thereto and at least two blind sensing elements, at least one blind sensing element being interspersed among the at least two sensing elements, each blind sensing element being shielded from incident infrared radiation from the object and providing a proportionate electrical signal in response to parasitic thermal fluxes. The output of the sensor array is a function of the infrared sensing elements and of the blind sensing elements such that parasitic thermal fluxes are at least partly compensated for.
Abstract:
A detector comprises a housing (1), a pyroelectric array sensor (2) mounted within the housing, a heater (4) associated with the pyroelectric array sensor, and control means (6) for varying the power supplied to the heater to control the temperature of the pyroelectric array sensor relative to the ambient temperature in order to minimise the rate of change of temperature of the pyroelectric array sensor and to keep a predetermined difference between the temperature of the pyroelectric array sensor and the ambient temperature.
Abstract:
Purging of a light beam path in an effective manner that minimizes the affect of the purging requirement on system throughput. In one embodiment, the invention is incorporated into a birefringence measurement system that has several components for directing light through a sample optical element and thereafter detecting and analyzing the light. The segment of the beam path through the sample is isolated to reduce the volume that requires continual purging.
Abstract:
This portable light source apparatus accommodates a deuterium lamp 10 in a lamp box 42 and, at the same time, in a housing 41 in order for the influence of temperature changes in the outside air to become very small. Namely, the deuterium lamp 10, which is susceptible to changes in temperature, is enveloped not only by the lamp box 42 but also by the housing 41, thereby being accommodated in a double shield structure. As a result, the temperature change of the housing 41, which is the most likely to be affected by the outside air, is harder to be transmitted to the deuterium lamp 10, whereby the latter can be utilized without taking account of the changes in weather during outdoor operations or influences of air conditioners and the like during indoor operations. Further, the deuterium lamp 10 can be inserted into and removed from the lamp box 42 from thereabove, so that operations of replacing the lamp 10 become easier even when the housing 41 is made compact, whereby the light source apparatus can be carried easier outdoors and in the field.
Abstract:
The invention provides a device for measuring radiation, as well as a method for measuring with the device, and a controllable lighting system with the device. The device (l') has a side wall (2) with a sensor (5, 5'), a radiation entrance opening (4'), and optionally a top wall (9) and bottom cap (10). The sensor is sensitive only to indirect radiation that is reflected at a reflection area, such as a ring (12a - 12b). The device is not sensitive to dust deposition, because most dust is blocked by the side wall (2), while any other dust will pass the sensor surface and reflection area(s) on air currents parallel thereto, without any deposition of dust or dirt. Hence the sensor will give more reliable measurements, even in dusty environments. The method involves orienting the device with respect to the light to be measured and to possible currents. The controllable lighting system involves measuring light levels with the device, and having a control unit control one or more lamps on the basis of those measurements.
Abstract:
A method of visually detecting a leak of a chemical emanating from a component. The method includes: aiming a passive infrared camera system towards the component; filtering an infrared image with an optical bandpass filter, the infrared image being that of the leak; after the infrared image passes through the lens and optical bandpass filter, receiving the filtered infrared image with an infrared sensor device; electronically processing the filtered infrared image received by the infrared sensor device to provide a visible image representing the filtered infrared image; and visually identifying the leak based on the visible image. The passive infrared camera system includes: a lens; a refrigerated portion including therein the infrared sensor device and the optical bandpass filter (located along an optical path between the lens and the infrared sensor device). At least part of a pass band for the optical bandpass filter is within an absorption band for the chemical.
Abstract:
Sensing in an elevated-temperature environment is provided using a sensor system having a sensor housing with an exterior wall with a window-support region having an outwardly facing external face, and a window through the window-support region of the exterior wall and affixed to the exterior wall. A sensor unit contained within the sensor housing receives an input signal through the window. A thermal-insulation layer is on the external face of the window-support region of the exterior wall at a location immediately adjacent to the window. The sensor system is operated in an environment wherein the window-support region of the exterior wall is heated to a temperature of greater than about 100 °C in the event that no thermal-insulation layer is present. In a typical application, the sensor system is attached to an aircraft such that the external face is in a forward-facing orientation, and the aircraft is operated such that the external face is heated by aerodynamic heating.