Abstract: An infrared attenuation measuring system, for the quantitative determination of the concentration of one or more components in an aqueous fat-containing sample, such as milk, by an infrared attenuation technique. The system comprising a set of waveband-related parameters containing information enabling the system to calculate the concentrations substantially independent of the degree of homogenization of the fat-containing sample, and/or to determine the degree of homogenization of the sample. The parameter set contains parameters which are related to wavebands containing a high degree of information about the homogenization degree of the sample. This may be wavebands containing little information about the chemical components of the sample, and/or wavebands containing a substantial amount of information about the chemical components of the sample. The system is calibrated with aqueous fat-containing samples with different degrees of homogenization.

Abstract: The number of bacteria in a cell population comprising bacteria and somatic cells is determined by concentrating the bacteria and the somatic cells on the surface of a substrate of a filter material, such as a membrane filter, rupturing the somatic cells by treatment with a medium which is not in osmotic balance with the medium inside the cells, such as water which here constitutes a hypotonic medium, and removing or inactivating their ATP, establishing an extraction chamber having an inner wall which is partly defined by the bacteria-bearing surface of the filter material and therein extracting the ATP from the bacteria with a medium containing a surfactant, such as a quaternary ammonium compound, capable of perforating the cell walls of the bacteria, adding luciferin and luciferase and transferring the medium to a measuring chamber, determining the amount of ATP by measuring the light emitted as a result of the luciferin/luciferase reaction and expressing the amount of ATP as the number of bacteria present

Abstract: The concentration of urea in a concentration range of 0-0.1% in a milk sample containing at least 1% fat, at least 1% dissolved lactose, and at least 1% protein, is determined with an accuracy better than 0.007%, expressed as Standard Error of Prediction, by an infrared attenuation measuring technique, by determining, on the sample, the attenuation in the region of infrared radiation from 1000 cm.sup.-1 (10.0 .mu.m) to 4000 cm.sup.-1 (2.50 .mu.m), at least one determination being made in a waveband in the region from 1000 cm.sup.-1 (10.0 .mu.m) to 1800 cm.sup.-1 (5.56 .mu.

Abstract: The invention relates to a liquid analyzing apparatus, especially for use in determining the fat content of milk samples. The apparatus comprises manually operated dosage syringes or pumps for mixing diluent and liquid sample in a predetermined relationship, a manually operable homogenizer for providing homogenized mixture to photometric measuring means including a cuvette. The homogenizer and the photometric measuring means are arranged within a temperature controlled block or body made from a heat conductive material. The homogenizer may comprise a piston pump having a piston provided with an O-ring and rigidly connected to a piston rod oscillating angularly in operation.