Abstract:
A device for sustaining a plasma in a torch is provided. In certain examples, the device comprises a first electrode configured to couple to a power source and constructed and arranged to provide a loop current along a radial plane of the torch. In some examples, the radial plane of the torch is substantially perpendicular to a longitudinal axis of the torch.
Abstract:
Methods and systems for real-time monitoring of optical signals from arrays of signal sources, and particularly optical signal sources that have spectrally different signal components. Systems include signal source arrays in optical communication with optical trains that direct excitation radiation to and emitted signals from such arrays and image the signals onto detector arrays, from which such signals may be subjected to additional processing.
Abstract:
A device for sustaining a plasma in a torch is provided. In certain examples, the device comprises a first electrode configured to couple to a power source and constructed and arranged to provide a loop current along a radial plane of the torch. In some examples, the radial plane of the torch is substantially perpendicular to a longitudinal axis of the torch.
Abstract:
Methods and systems for real-time monitoring of optical signals from arrays of signal sources, and particularly optical signal sources that have spectrally different signal components. Systems include signal source arrays in optical communication with optical trains that direct excitation radiation to and emitted signals from such arrays and image the signals onto detector arrays, from which such signals may be subjected to additional processing.
Abstract:
An apparatus and method for measuring the gloss of a surface with a light source projecting light in the direction of the surface and a light-sensitive sensor receiving the light reflected from the surface and converting it into an electrical signal value. A memory storing a program for calculating the characteristic gloss value, a computer for calculating a characteristic gloss value from the electrical signal value, and a display for visually displaying the calculated characteristic gloss value are provided. Five or more reference value pairs are stored in the memory, each pair consisting of a reference characteristic gloss value and a corresponding reference electrical signal value measured by the apparatus on the basis of the reference surface. The measured electrical signal value is compared with the reference signal values and at least the next higher and the next lower value for interpolating the measured gloss.
Abstract:
A spectrophotometer apparatus (200) is adapted to provide spectral reflectance measurements of an object sample (236) under test, particularly optical characteristics of colored surfaces comprising metallic or pearlescent particles. The apparatus (200) comprises a source light (226) and a reflection optics assembly. Signals representative of reflected light are analyzed and data is generated representative of the spectral response characteristics of the object sample (236). The apparatus (200) employs a plurality of fiber optic bundles (248, 250, 252) for receiving light reflected from the object sample (236), with each of the fiber optic bundles (248, 250, 252) being positioned at one of a corresponding plurality of fixed angles different from the angle of illumination of the source light (226). Reflectance is measured at each angle by sequential switching such that light is impaired from being received by all but a subset of the plurality of multiple angles. Light received from the fiber optic bundles is transferred to a single array of integral interference-filter/photodiode devices (284) which modulate the light and determine the spectral characteristics thereof. With the use of fiber optic devices, a single source of illumination and a single optical detector arrangement, the spectrophotometer apparatus (200) is employed within an optimally small packaging configuration, and the apparatus (200) can be maintained in a portable mode while maintaining relatively high accuracy and repeatability.
Abstract:
A measuring apparatus of the present invention measures the constituent concentration of a specimen after loading into the apparatus a test piece having a test material which develops coloring as a result of a reaction with the constituents of a specimen. When the apparatus detects that the test piece having the test material has been loaded, it automatically begins to measure the constituent concentration of the specimen. That is, after the loading of the test piece is detected, a predetermined time period is measured. During this time measurement, the time period is displayed at a predetermined time interval. After the time measurement of this predetermined time period is terminated, the test material is irradiated with a light, and the intensity of the light from the test material is detected. The constituent concentration of the specimen applied to the test material can be determined on the basis of the reflected light intensity thus detected. Furthermore, this measuring apparatus can detect a reverse insertion of a test piece, and is constructed so as to disable the measurement of the constituent concentration of a specimen if supplementary information to be stored along with measurement information has not been set.
Abstract:
A method and apparatus for determining the characteristics of materials, particularly of semi-conductors, semi-conductor heterostructures and semi-conductor interfaces by the use of photoreflectance, in which monochromatic light and an acousto-optically modulated light beam reflected from the sample is detected to produce a d.c. signal and an a.c. signal, whereby the d.c. signal is applied to one input of a computer and the a.c. signal is used with another input of the computer which controls the light intensity of the monochromatic light impinging on the sample to maintain the d.c. signal substantially constant. The modulation frequency of the modulated pump beam and/or the wavelength of the monochromatic light can also be varied by the computer. Information about trap times can be obtained by determining the dependence of the in-phase signal on the pump modulating frequency, respectively.
Abstract:
Improved infrared detectors for use in device such as capnographs are provided. A preferred embodiment of an infrared detector of the invention is comprised of paired thermopiles, connect in opposed relation to each other, which are preceded by an analytical or reference filter for passing a desired wavelength and a neutral density filter in the optical path of one of the thermopiles in the pair. The difference between the outputs can be used to eliminate the effects of background thermal noise, thereby improving performance of the detector. Preferably, a reference channel and an analytical channel are provided so that the respective differences between the detectors in each pair can be used to further cancel the effects of background thermal noise.
Abstract:
A densitometer apparatus (200) is disclosed and is adapted to provide color density measurements of opaque materials. The densitometer apparatus (200) comprises a light source unit (202) having a source light (204) projecting light through a collimating lens (206). Light rays transmitted through the collimating lens (206) project through an aperture (208). The rays are projected onto an irradiated area surface of an object sample (212) under test. Electromagnetic radiation in the form of reflected light rays (214) are reflected from the sample (212). The reflected light rays are directed through a spectral filter apparatus (216) and impinge on receptor surfaces of photo-voltaic sensor cells (232, 234, 236). The sensors (232, 234, 236) generate electrical currents having magnitudes proportional to the intensities of the sensed light rays. The electrical signals are applied as input signals to amplifiers (244, 246, 248), with the amplified signals applied as input signals to a multiplexer (256) for time multiplexing each of the output signals from the amplifiers. The resultant multiplexed signal is applied as an input signal to an A/D converter (264) to convert the analog multiplexed signal to a digital signal. The digital output signal from the A/D converter (264) is applied as a parallel set of binary information signals to a central processing unit (266). Actual measurements of color reference patches are processed so as to solve for unknown constants of a set of equations representing correction or compensation factors functionally dependent on actual reflectance measurements. The correction factors are then utilized by the densitometer apparatus (200) to compensate measurements of actual object samples.