In an automatic chemical testing apparatus in which different chemical tests are performed selectively on one or more aliquots of each of a number of samples, samples are placed in successive ordinal positions for sequential aspiration into the apparatus for testing. Selection means in a selection panel...http://www.google.de/patents/US4166095?utm_source=gb-gplus-sharePatent US4166095 - Selective test selection and indicator means in an automatic chemical testing apparatus
