Abstract: A method for photometrically measuring a reaction process at a darkened measuring station which contains a sample having an unknown quantity of a substance which acts as a reaction partner with a reagent. The sample is provided with a first reagent which acts as a reaction partner with a reaction partner present in the sample. A first photometric measurement of the sample is taken at the darkened measuring station to measure the reaction process between the first reagent and the reaction partner in the sample, and this first measurement is used for computation. At least one additional reagent which differs from the first reagent and which constitutes a further reaction partner is added to the sample at the darkened measuring station after the first photometric measurement. A photometric measurement of the sample is conducted after the addition of each additional reagent and during the course of a reaction between reaction partners then present.

Abstract: A method and apparatus for automatically stabilizing drift in radiation measurements which employ a detector whose pulse amplitude corresponds to the energy absorbed by the detector, involves the use of a peak produced in the pulse amplitude spectrum by individual electrons. The peak is at the low energy end of the spectrum and is drift stable. It can be produced by for example a direct or indirect light source such as a light emitting diode, by the phosphorescence of e.g. a sodium iodide crystal used as a scintillation crystal in nuclear radiation measurement, or by spontaneous surface emission within the detector, which is suitably a photomultiplier. The apparatus includes a determination device to determine the position of the drift stable peak and a control device to control the detector in response to the output of the determination device.

Abstract: The present invention relates to a method and a circuit for determining the quench corrected counting efficiencies of samples emitting beta radiation, secondary electrons or the like having an undetermined proportion of chemical and color quenching in a liquid scintillation counter using an external standard.

Abstract: To measure the nuclear radiation of a sequence of radioactive samples, magazines that hold sample containers are removably positioned in shuttles, some of which are driven step-by-step by a toothed belt that engages racks on the sides of the shuttles from one compartment to another through a measuring station, with the shuttles that are being driven by the belt driving other shuttles not in engagement with the belt at that time. In the measuring station, the sample containers are released from the magazines one at a time through openings in their bottoms and lowered by a reciprocable support to a position adjacent to a radiation detector for the measurement, after which they are raised by the support to the magazine and the shuttle is driven one more step to the next position.