The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 22, 1991
Filed:
Oct. 09, 1990
Bernhard Huber, Uberlingen, DE;
Bodenseewerk Perkin Elmer GmbH, Uberlingen, DE;
Abstract
The control apparatus controls the lowering motion of an aspirator tube into a sample vessel in an automatic sample dispenser in a manner such that the smallest possible portion of an external surface of the aspirator tube is wetted by a liquid present in the sample vessel. A servo drive lowers the aspirator tube into the sample vessel. A sensor arrangement containing a single light guide, a light transmitter and a photoelectric receiver is associated with the aspirator tube and responds to light reflections at the liquid surface upon immersion of the lower aspirator tube end into the liquid. The light guide guides the propagating light beam and a returning reflected light beam. An electronic control controls the advancement of the aspirator tube via the servo drive into a position in which a predetermined short length in the region of the lower aspirator tube end dips into the liquid. When the liquid level drops due to aspiration of liquid into the aspirator tube, the lower end of the latter follows just this drop of the liquid level so that the aspirator tube continuously remains immersed into the liquid but only with the short length at its lower end.