Introduction of UV-Visible Spectrophotometer Type

At present, the instrument structure of UV-visible spectrophotometer is generally divided into three types: single beam, dual beam, and dual wavelength.

(a) The single beam spectrophotometer commonly used single beam spectrophotometer has 721 type, 722 type, 723 type, 724 type, 727 type and so on. Commonly used UV-visible spectrophotometers are 751G type, 752 type, 753 type, 754 type, 756M type and so on. The Du70 and Pu8700 models abroad are also single-beam spectrophotometers. *Single beam refers to the light emitted from the light source, through the monochromator, etc.—a series of optical components that pass through the absorption cell and finally shine on the detector. Beam of light. It only has one beam of monochromatic light (the beam can only alternately pass the reference solution, sample solution), a cuvette, and a photoelectric converter. When working, a light path, first through the multi-solution, and then through the sample solution for light intensity measurement denier.

The single-beam spectrophotometer is characterized by its simple structure and low price. It is mainly suitable for quantitative analysis. The measurement results are greatly affected by the fluctuation of the power supply, and it is easy to bring large errors to the measurement results. Therefore, they are limited in their position. Generally speaking, the single-beam UV-VIS spectrophotometer is not suitable for the higher requirements of the pharmaceutical industry and quality inspection.

(B) of the double-beam spectrophotometer common double-beam UV-visible spectrophotometric juice are mainly 710 type, 730 type, 7MMc type, 760cRT type, TYt880 type, TY8500 type, TU-1901 type, TU-l coffee type, UVL2t0 type , UV/See -1, UY21 叨, t 乃 L763, t 正 / -2450, t 八/-3101, U-3400, Lambda9, Lilnbda9, CaV5, CgY6 Coffee, Cav500 Type and so on.

Dual-beam spectrophotometric juice is an ultraviolet-visible spectrophotometer with two monochromatic lights. The optical path design is basically similar to the single beam spectrophotometer. The difference is that an optical cutter is added between the monochromator and the absorption and relaxation, and its function is to alternately divide a beam of light into two equal-intensity two-beam lights at a certain frequency, so that all the way through the reference solution and the other way through the sample solution. . The detector then alternately receives the reference signal and the sample signal. The received optical signal is converted into an electrical signal, amplified by a preamplifier, and further demodulated, amplified, compensated, etc., and finally displayed by the display system. Its light path system.

(C) dual-wavelength spectrophotometer dual-wavelength spectrophotometer uses two monochromators, you can get two different wavelengths of monochromatic light at the same time, its light path. The light emitted by the light source is separated by two monochromators respectively, the wavelength is 4: and 4z monochromatic light, through the cleaver, the two lights are alternately irradiated at a certain time interval to the same absorption cell containing the sample solution, and the detector shows the test solution at wavelengths 4 and 42 The transmittance or absorbance. The dual-wavelength spectrophotometer can not only measure high-concentration samples and multi-component mixed samples, but it is more sensitive and selective to single-wavelength determination when determining turbidity samples. In the dual-wavelength measurement, two wavelengths of light pass through the same absorption cell, and pJ eliminates errors due to absorption of different parameters, positions, dirt, and preparation of a reference solution, thereby significantly improving the accuracy of the measurement.