Specrrochimica Acta, Vol. 45A, No. 6, pp. i-iii, 1989 Pergamon Press plc. Printed in Great Britain.

NEW PATENTS

This Section contains abstracts and, where appropriate, illustrations of recently issued United States patents and published patent applications filed from over 30 countries under the Patent Cooperation Treaty. This information was obtained from recent additions to the Pergamon PATSEARCH online database in accordance with interest profiles developed by the Editors. Further information about Pergamon PATSEARCH@ can be obtained from Pergamon Orbit InfoLine Inc., 8000 Westpark Drive, McLean, Virginia 22102 U.S.A.

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4782297

ELECTRON SPIN RESONANCE SPECTROMETER

Klaus-Dieter Schmalbein, Kgra/a/ roly Holczer, Marxzell Burbach, Federal Republic Of Ger- many assigned to Bruker Analytische Mebtech- nik GmbH Silberstein

An electron spin resonance spectrometer com- prises a resonator arranged in a magnetic field of constant strength and high homogeneity and containing a sample. The resonator can be sup- plied, via a microwave bridge, with high-power microwave energy in the form of an intermittent signal. Measuring signals emitted by the resonator can be supplied to detector arrange- ments and signal evaluation arrangements. In order to be able to cut a pulse-shaped output signal of the microwave power amplifier off sharply at its trailing edge, the attenuator is designed as a switching stage comprising a cir- culator whose input is connected to the output of the microwave power amplifier. A subsequent circulator connection is wired up to a series con- nection comprising a microwave switching diode that can be switched via a control input and a waveguide termination, and another subsequent circulator connection is connected to the micro- wave bridge (FIG. 10).

4786171

SPECTRAL ANALYSIS APPARATUS AND METHOD

David A LeFebre, Roger Schirmer assigned to Guided Wave Inc

Apparatus and method for measuring the abs- orbance of fluid samples. The length of the light path through the sample is adjusted to optimize the amount of light absorbed by the sample, and the absorbance of the sample is calculated from the length of the path and the amount of light absorbed. Accurate measurement of the abs- orbance of the fluid may be made by taking measurements at two different path lengths, since light level changes due to fouling of the op- tical windows or other slow changes in the op- tical train are independent of the path length, while that of the fluid varies proportionally with the path length. A preferred form of probe in- cludes a cylindrical cell having an exposed variable path length sensing portion at one end and an actuator for varying the spacing at the other end, and a cylindrical cell insertion tube having seals and a large valve mechanism to per- mit removal of the probe without loss or escape of the fluid being measured.

4787750

GAS SPECTROMETER CONSTRUCTION HAVING AN

IMPROVED ALIGNMENT FEATURE

Robert L Nelson, William H McIntyre, William Danley assigned to Westinghouse Electric Corp

An across-the-stack gas analyzing spectrometer has a radiation source assembly including a cylindrical tube 22 having, in succession from its outer end toward the stack end a radiation emis- sion assembly 28, a first lens assembly 30, and an AOTF assembly, all in optically aligned arrange-