Cell for use in radiation absorption analysis

Claim 1

AN ABSORPTION CELL COMPRISING OPPOSED FRONT AND BACK WINDOW PLATES OF A MATERIAL TRANSPARENT TO A PREDETERMINED RADIATION, A RELATIVELY THIN SPACER BETWEEN SAID FRONT AND BACK WINDOW PLATES HAVING A GENERALLY CENTRALLY LOCATED APERTURE EXTENDING THROUGH SAID SPACER, FRONT AND BACK PRESSURE-APPLYING MEANS FOR FORCING SAID FRONT AND BACK WINDOW PLATES INTO FLUID-TIGHT SEALING ENGAGEMENT WITH SAID SPACER SO THAT A FLUID-TIGHT CHAMBER IS FORMED BETWEEN SAID PLATES BOUNDED BY THE PERIPHERY OF THE APERTURE IN SAID SPACER, THE AREAS OF CONTACT BETWEEN SAID PRESSURE-APPLYING MEANS AND SAID WINDOW PLATES BEING LOCATED OUTWARDLY OF THE PERIPHERY OF THE APERTURE IN SAID SPACER SO THAT SAID WINDOW PLATES ARE FREE OF OBSTRUCTION TO THE PASSAGE OF RADIATION THERETHROUGH AT LEAST THROUGHOUT THE AREA OF THE SAID PLATES WHICH IS COEXTENSIVE WITH SAID FLUID-TIGHT CHAMBER, MEANS FOR ESTABLISHING COMMUNICATION WITH SAID FLUID-TIGHT CHAMBER SOLELY THROUGH SAID SPACER INCLUDING ONE OR MORE TUBULATE PORTS IN THE SAID SPACER AND ONE OR MORE HYPODERMIC NEEDLES COOPERABLE WITH SAID ONE OR MORE PORTS TO DELIVER OR WITHDRAW FLUID FROM SAID SEALED CHAMBER, AND MEANS FOR CLOSING SAID MEANS FOR ESTABLISHING COMMUNICATION TO SAID FLUID-TIGHT CHAMBER, SAID SPACER BEING MADE OF A MATERIAL SUFFICIENTLY RIGID AND NON-COMPRESSIBLE TO PREVENT COLLASPE OF SAID PORTS WHEN PRESSURE SUFFICIENT TO FORM A FLUID-TIGHT SEAL BETWEEN SAID SPACER AND WINDOW PLATES IS APPLIED TO THE LATTER.