The essence of urine analyzer testing principle is light absorption and reflection. The liquid sample is directly added to the multi linked reagent belt with different solidified reagents. The corresponding chemical components in the urine change the color of the modules containing various special reagents on the multi linked reagent belt. The color depth is proportional to the concentration of specific chemical components in the urine sample; Place the multiple test strip in the urine analyzer colorimetric injection tank. Each module is illuminated by the instrument light source in turn and generates different reflected light. After receiving the light signals of different intensities, the instrument converts them into corresponding electrical signals. Then the reflectance of each test item is calculated by the microprocessor (CPU), and then corrected to the measured value after comparing with the standard curve. Finally, the results are automatically printed in a qualitative or semi quantitative manner.
This kind of instrument is generally controlled by computer, and the color change on the test strip is measured by the way that the sphere area analyzer receives the dual wavelength reflected light for semi quantitative measurement. There are several reagent pads containing various reagents on the reagent belt, which react independently with the corresponding components in urine and display different colors. The depth of the color is proportional to a certain component in urine. There is another "compensation pad" in the reagent belt, which is used as the background color of urine to compensate for the errors caused by the change of colored urine and instruments.
Place the reagent strip adsorbed with urine in the colorimetric tank of the instrument. Various reagent pads that have produced chemical reaction on the reagent strip are irradiated by the light source, and the reflected light is received by the spherical area analyzer. The photocell of the spherical area analyzer is irradiated by the reflected double wavelength light (the measurement light passing through the filter and a reference light). The selection of each wavelength is determined by the detection items.
The instrument usually calculates the reflectance automatically according to the following formula, and then compares it with the standard curve to automatically find and print the corresponding results of various components. The content of a component in urine is high, and the reflected light of the corresponding reagent pad is dark, otherwise it is strong.
Reflectance fraction: R (%) =tm Cs/TsCm × 100%
Where R (%) is reflectance; TM is the reflection intensity of the reagent pad to the measured wavelength; TS is the reflection intensity of the reagent pad to the reference wavelength; Cm is the reflection intensity of the measured defect length of the more accurate pad pair; CS is the reflection intensity of the calibration to the reference wavelength.