Detection chamber of evaporative light scattering detector

Abstract

The invention discloses a detection chamber of an evaporative light scattering detector, which can improve background light noise of an instrument and increase signal-to-noise ratio of the instrument, and comprises a detection chamber main body, a detection object inlet is arranged at the axial end part of the detection chamber main body, an excitation light source is arranged on the side wall of the detection chamber main body, a light source absorption trap is arranged on the side wall of the detection chamber opposite to the excitation light source, a detector lens barrel is arranged on the detection chamber main body, the other end of the detector lens barrel is connected with a photoelectric detection unit, the detector lens barrel comprises a barrel body arranged on the detection chamber main body and an emergent light bar detachably arranged at one end, far away from the detection chamber main body, of the barrel body, a scattering light shield is arranged at a light inlet of the detector lens barrel, the scattering light shield comprises a cylinder part connected with the detector lens cone and a cone part at the front end, the cone angle of the cone part is smaller than 30 degrees, the plane where the outer side edge of the cone part is located is parallel to light rays of the light source, and the outer side edge is located at the boundary of the scattering generation area.

Description

technical field [0001] The invention relates to a detection chamber of an evaporative light scattering detector. Background technique [0002] After the aerosol formed by the atomization unit and evaporation unit of the evaporative light scattering detector enters the detection chamber, under the illumination of the light source, two types of scattering will be produced, Mie scattering and Rayleigh scattering, where Mi Scattering is the main scattering detected by this type of detector, and the schematic diagram of its scattering form is shown in figure 1 shown. [0003] Among them, the Mie scattered light is mainly concentrated in the direction illuminated by the light source, so this brings great difficulties to the detection of the signal. If the photoelectric detection unit is placed in the front of the light source, at this time, due to the signal If it is too strong, it will cause the photodetection unit to "blind" and cannot detect the signal. If it is placed in the...

AI Technical Summary

Problems solved by technology

However, there is still the problem of large local light noise at this time. The background light noise comes from the light source. At present, this type of instrument mainly uses laser light source, light-emitting diode light source or halogen light source. However, no matter which light source is used, and after Due to the processing of various optical devices, some light from the light source will always enter the photodetection unit, resulting in the superposition of light from the light source and scattered light

Since the light source itself is very strong, and the scattered light is very weak, this part of the light from the light source entering the detection unit will have a relatively large impact on the noise floor

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