Abstract:
A passive infrared detector has a first sensor (1) for generating an infrared signal, representative of the difference in temperature between a heat source and the background environment of the detector, a second sensor (3), influenced by the ambient temperature in the detector, and an evaluation circuit (2) for processing the infrared signal. The evaluation circuit contains a temperature compensation (4) for influencing the sensitivity of the detector as a function of the ambient temperature. The temperature compensation (4) is designed in such a way that the sensitivity of the detector is not directly influenced by changes in the ambient temperature. Influencing of the sensitivity of the detector takes place with delay and/or as a function of the speed of the change in the ambient temperature.
Abstract:
Method and apparatus are provided for visibly outlining the energy zone to be measured by a radiometer. The method comprises the steps of providing a laser sighting device on the radiometer adapted to emit more than two laser beams against a surface whose temperature is to be measured and positioning said laser beams about the energy zone to outline said energy zone. The apparatus comprises a laser sighting device adapted to emit more than two laser beams against the surface and means to position said laser beams about the energy zone to outline said energy zone. The laser beams may be rotated about the periphery of the energy zone. The laser beams may be rotated about the periphery of the energy zone. In another embodiment, a pair of laser beams are projected on opposite sides of the energy zone. The laser beams may be further pulsed on and off in a synchronized manner so as to cause a series of intermittent lines to outline the energy zone. Such an embodiment improves the efficiency of the laser and results in brighter laser beams being projected. In yet another embodiment, a primary laser beam is passed through or over a beam splitter or a diffraction grating so as to be formed into a plurality of secondary beams which form, where they strike the target, a pattern which defines an energy zone area of the target to be investigated with the radiometer. Two or more embodiments may be used together. A diffraction device such as a grating may be used to form multiple beams. In a further embodiment, additionally laser beams are directed axially so as to illuminate the center or a central are of the energy zone.
Abstract:
A method and apparatus for monitoring the condition of the thermal barrier coating on turbine blades and vanes is provided. The coating is monitored with ultraviolet sensors which can detect ultraviolet radiation emitted from electrical discharges and glow coronas at the surface of the blades and vanes. Such electrical glow discharges and coronas are the result of friction electricity found at the surface of blades and vanes, and are also due to the high pressure, temperature and velocity conditions within the turbine. As the thermal barrier coating deteriorates, the electrical discharges and glow coronas and associated UV emissions decrease in magnitude or have other characteristic changes, thus permitting monitoring of the corona to detect changes in the coating over time.
Abstract:
In a data carrier (1) having an electrical circuit (2), indication means (3) are implemented by means of the electrical circuit (2), which means are arranged so as to determine the occurrence of a change in a parameter influencing the data carrier (1) in relation to at least one threshold value, the at least one threshold value dividing a first parameter range from a second parameter range, and which means are arranged so as to give a permanent indication of the change during the time following the first occurrence of said change.
Abstract:
A microbolometer for the detection of infrared radiation that has a substrate and an array of sensor elements fixed relative to the substrate. In one embodiment, at least some of the sensor elements are less thermally isolated from the substrate than others. The less thermally isolated sensor elements are selected when transients are expected to exist within the sensor array. In another embodiment, all of the sensor elements are deselected when transients are expected.
Abstract:
A microbolometer array has pixels with a thin platform of silicon dioxide having a metal absorber layer, and having a resonant gap with a substrate reflector. The pixel resistor of vanadium oxide has low total resistance with metal contacts on opposite edges.
Abstract:
An infrared ear thermometer includes a detector head housing, a heat sink, a recess formed in the heat sink, a thermopile sensor mounted within the recess, a thermistor, and temperature determination circuitry. The recess defines an aperture that limits the field of view of the thermopile sensor. The thermal capacities and conductivities of the heat sink and the thermopile sensor are selected so that the output signal of the thermopile sensor stabilizes during a temperature measurement. A method of determining temperature using the ear thermometer takes successive measurements, stores the measurements in a moving time window, averages the measurements in the moving window, determines whether the average has stabilized, and outputs an average temperature. A method of calculating a subject's temperature determines the temperature of a cold junction of the thermopile, looks up a bias and slope of the thermopile based upon the temperature of the cold junction, measures the output of the thermopile, and calculates the subject's temperature based upon a linear relationship between the output and the subject's temperature. The linear relationship is defined by the bias and the slope.
Abstract:
A thermal imaging camera having improved durability and ergonomic features including generally a seamless housing encompassing a thermal imaging core, a first handle, and a battery compartment. The housing is preferably positioned at a first end of the first handle and the battery compartment is positioned at the opposite end of the first handle. By positioning the first handle intermediate between the housing and the battery compartment, the center of gravity of the thermal imaging camera coincides generally with the handle when the thermal imaging camera is in use, that is when batteries are present within the battery compartment. The camera can also include a second handle positioned between the housing and the battery compartment, the second handle is preferably oriented generally parallel to and spaced apart from the first handle to facilitate passing of the thermal imaging camera between users. The camera also has improved water resistance, shock-resistance and other operational features.
Abstract:
A trunk section 11 constituted by a rigid member and a thin film section 12 having infrared permeability can be obtained by integral moulding using the same resin material, and the outer peripheral surface of the trunk section 11 and the outer peripheral surface of the thin film section 12 are formed such that the outer peripheral surfaces are smoothly connected to each other. The connection portion therebetween is free from a step or a seam.
Abstract:
An image reading apparatus having a visible light source for emitting visible light, an invisible light source for emitting invisible light, an imaging optical system for irradiating a document by these light sources to form optical images of the document, and a CCD for photoelectrically converting the optical images Of the document turns on the visible light source to acquire a visible light image signal by the CCD. Then, the apparatus turns on the invisible light source to acquire an invisible light image signal by the CCD. After the invisible light image signal is acquired, the apparatus turns off the invisible light source, and turns on the visible light source regardless of whether to read the document.