Abstract: The invention provides a photometric method of determining courses of reaction in a specimen, in which method the intensities of the transmitted light and of the stray light are measured, wherein the two intensities are measured simultaneously and the electrical signals corresponding to the transmitted light and to the stray light are combined to form one signal. The invention makes it possible to perform reliable measurement even with low levels of transmitted and stray light.The method is preferably used in determining the coagulation times of blood. Apparatus for carrying out the method is also disclosed.

Abstract: A device for reading the results of centrifugal separation of test samples such as samples of blood. The centrifugal separation apparatus is provided with a housing having a hinged cover having a magnifying lens built into it, either as a lens shaped portion of a plastic cover, or as a separate glass lens attached to the cover. Arms on the hinged cover, engaging with abutment portions on a stationary part of the housing, define a position of the cover which is most appropriate for reading the results.

Abstract: A device for reading the results of centrifugal separation of test samples such as samples of blood. The centrifugal separation apparatus is provided with a housing having a hinged cover having a magnifying lens built into it, either as a lens shaped portion of a plastic cover, or as a separate glass lens attached to the cover. Arms on the hinged cover, engaging with abutment portions on a stationary part of the housing, define a position of the cover which is most appropriate for reading the results.

Abstract: A rotor, adapted for rotation at high speeds, has symmetrically arranged radial channels for receiving tubular containers of material to be evaluated, such for example as samples of blood. The outer end of each radially extending container is placed against a resilient abutment at the rim of the rotor, and its inner end is placed against a clamping collar arranged centrally of the rotor and having limited movement in the direction of the axis of rotation. In the initial loading position, the tubular containers are inclined upwardly from the rim toward the center of the rotor. They are clamped firmly into position on the rotor by axial movement of the clamping member which carries the inner ends of the containers downwardly, to force the containers slightly radially outwardly, compressing the resilient abutments at their outer ends.