Abstract: A spectrometer includes a pair of crossed reflective gratings to effect a spectrally dispersed beam that is focussed to an array detector. The second grating is a plural grating with a surface formed of a first portion and a second portion. The first portion has a groove density for effecting ultraviolet in the dispersed beam. The second portion has a groove density for effecting visible radiation in the dispersed beam. A shutter blocks or exposes the second portion of the grating surface so as to select the first spectral range or the second spectral range for detection. The plural grating surface preferably may be contoured to compensate for aberrations in focussing of the beam to the detector. A computer may be used for selecting spectral lines for analysis, particularly selecting such lines in the second range that are not interfered with by the first range.

Abstract: An atomic emission spectrometer includes an induction coupled plasma generator and a detector system for detecting the radiation relative to spectral wavelength. A first mirror is on the longitudinal axis of the generator to receive axial radiation therefrom. A second mirror is disposed laterally from the generator so as to reflect radial radiation therefrom parallel to the longitudinal axis toward a third mirror disposed laterally from the longitudinal axis. The third mirror passes the radiation to a fourth mirror positioned adjacent to the axial radiation without interfering therewith so as to reflect the radial radiation to the first mirror. The first mirror is rotated to a first orientation to reflect the axial radiation into the detector system, or to a second orientation to reflect the radial radiation into the detector system.

Abstract: A novel solid state array detector is useful in an optical spectrometer of the type that includes a crossed dispersion system receptive of radiation for producing a pair of two dimensional displays of spectral lines characteristic of at least one atomic element. One display is ultraviolet and the other is visible. A solid-state chip has on the front surface a two dimensional array of photosensitive pixels receptive of radiation of selected spectral lines and proximate background radiation. The pixels are arranged in a plurality of sub-arrays with each sub-array consisting of at least one of the pixels and are positioned at a projection location on the front surface of at least one of the selected spectral lines. Electronic components formed on the chip among the sub-arrays are operatively connected to the pixels for producing readout signals correlating with intensities of the selected spectral lines.

Abstract: An atomic absorption spectrophotometer having a source, e.g., a hollow cathode lamp, of spectral radiation of a selected narrow band of wavelengths optically directed along an axis through an electrothermic sample atomizer and a field stop to a photoelectric detector. The sample atomizer is subjected to a substantially unipolar AC electromagnetic field having flux lines directed transversely to said axis to effect Zeeman splitting of the radiation into two orthogonally polarized components .pi. and .sigma.. Disposed in the optical path between the atomizer and detector is a stationary beam-splitting polarizer prism oriented so as to transmit the .sigma. polarized component and block the .pi. component. Mirrors are used exclusively in the optical systems so as to minimize the effect of dispersion and stray light.An electromagnet, used to generate the electromagnetic field, is connected to the AC power line in series with the diode and has a small capacitor connected across its coils.

Abstract: An improved optical chopper, developed particularly for use in a double beam atomic absorption spectrophotometer, receives light beams from two separate sources and sequentially switches them into two separate paths and instantly thereafter the second light beam enters the first path, followed immediately by the first beam entering the second output path and then the second beam entering the second path; alternatively, the chopper is arranged so that the first light beam enters the first output path followed by the first light beam entering the second output path, and then the second light beam enters the first path and the second light enters the second path; also, during one segment of the choppers cycle, both beams are blocked from both output paths.