An arrangement for the simultaneous qualitative or quantitative determination of several antigens in mixtures of antigens by immunoelectrophoresis in a matrix containing antibodies, by coating the support for the matrix with several matrix strips, one following the other and each containing a specific antiserum, and a process for the determination of several antigens in mixtures, wherein said arrangement is used.

A special plotting paper for determining the unknown concentration of a sample species in titrations utilizing Nernstian response sensing devices. The paper comprises lines defining a vertical and horizontal axis, a set of parallel vertical lines spaced equally apart, and a set of transverse lines spaced anti-logarithmically apart and skewed with respect to the horizontal axis. The intersection of the vertical lines with the horizontal axis forms a linear scale which represents the volume of tit...

An improved method and apparatus for determining the amount of luminescence of a test sample which luminesces when contacted with a luminescence-inducing material is described. The apparatus comprises a sample-holding means, a light-detecting means in the form of a photometer tube, a shutter means, all of these having a housing portion which when secured together provide a light-tight environment. The phototube provides a current having a value determined by the light output of the sample. Such ...

A system for the measurement of lengths of electrodes employed in electric arc furnaces wherein initially approximately accurate-length signals are obtained by adding a weight signal to a current derived buoyancy signal. Then a more accurate measurement is determined by averaging a number of such signals, sampled at times when an electrode has just been selectively elevated responsive to an arc current signal.

Blood serum containing cholesterol is treated with water and a reagent containing glacial acetic acid, acetic anhydride, and sulfuric acid to form a pink colored complex whose absorbance is proportional to the cholesterol concentration. The amount of cholesterol can be determined by measuring the optical density or absorbance of the colored complex at 500 nm. In order to produce the colored complex and prevent interference, for each unit volume of blood serum, 15-24 unit volumes of water and 200...

An apparatus for determining the temperature at which a transformation occurs in a castable material such as a latex emulsion, a plastisol, etc. The apparatus includes a thermally conductive test block including an elongated test surface thereon having a temperature gradient thereacross. Heat is applied to the test block at a plurality of spaced points therealong, and heat is removed from a plurality of points disposed between the heat input points. Means are provided to selectively control the ...

A device for determining the profile of a surface is disclosed. It comprises a beam arranged in a rotating plane about an axis of rotation, forming on the surface a light spot and scanning a sector of that plane. A detection system whose detection axis is situated in that plane cuts the beam near the surface and a system for measuring the angle formed by the axis of detection and the beam during the scanning when the light spot is situated on the detection axis is utilized.

An improved gas-sensing electrochemical cell for measuring hydrogen cyanide gas in a sample solution. The cell comprises a potentiometric silver ion-sensitive electrode and a reference electrode, both in contact with an internal standard solution comprising an aqueous solution of an argento cyanide complex. A hydrophobic hydrogen cyanide gas-permeable membrane separates the sample solution from the internal solution.

Standard deviation determining apparatus includes an integrator for integrating changes exhibited by a random variable, a circuit for selecting integrator output signals and a further circuit for averaging signals selected by the selecting circuit. The apparatus provides for periodic resetting of the integrator, for selecting integrator output signals occurring during predetermined time periods and for maintaining the integrator output constant in amplitude during the selecting of signals theref...

Homogeneity of bulk control serum is determined when making production fills of clinical chemistry control serum using a radioactive tracer in the bulk control serum tank. A radioactive tracer is added to the control serum along with any other added constituents. After standard bottles are filled, they are analyzed for radioactivity in a radiation counter for measuring the amount of radioactive tracer in each bottle and thereby determining the homogeneity of the contents of the bottles.