Automatic analyzer and standard solution for evaluating scattered light measurement optical system thereof

A method of adjusting a light quantity of a light source, comprising:

• providing an automated analyzer that has an LED light source, a cell that contains a reaction solution, and a detector that detects light which radiates from the light source to the cell and is scattered by the reaction solution in the cell, the cell having an optical path of 5 mm;
• irradiating the cell with the light source light with a quantity of light at a wavelength of 700 nm;
• dispensing a standard solution to the cell, the standard solution comprising a solvent and an insoluble carrier at a concentration at which transmittance is in a range of 10% to 50% at an optical length of 5 mm in the cell, wherein
• the insoluble carrier is a latex particle having a grain size of 250 to 350 nm;
• detecting, by the detector, light which radiates from the light source to the cell, to which the standard solution is dispensed, and is scattered by the standard solution in the cell as a light quantity received, wherein
• the solvent in the standard solution is a glycerin aqueous solution containing 15% to 25% by weight of glycerin;
• adjusting the light quantity of the light source such that the detector outputs a predetermined value, wherein the method to adjust the light quantity comprises determining the predetermined value based on the grain size and concentration of the standard solution,
• measuring the light quantity received by the detector,
• retrieving a stored preset base count light quantity from a circuit obtained when the light quantity received was 0,
• determining a light detector output value by adding the base count light quantity to the light quantity received, and
• adjusting the quantity of light emitted by the light source by controlling a driving current of the LED such that the light detector output value is equal to the predetermined value.