Multi channel spectrophotometerIt is a key equipment in the field of optical measurement and analysis, which integrates advanced optical and electronic technologies and can efficiently and accurately obtain spectral information of substances. It plays an important role in many industries. It is analyzed based on the absorption, emission, or scattering characteristics of substances towards light of different wavelengths. The built-in optical system of the instrument first decomposes the composite light emitted by the light source into monochromatic light arranged in wavelength order. The multi-channel detector can simultaneously detect and convert light signals of different wavelengths, convert the light signals into electrical signals, and then obtain spectral data through the data processing system.
Multi channel spectrophotometerIts components mainly include the following core modules, which work together to achieve spectral acquisition and analysis:
1、 Light source system
Function: Provide excitation or illumination light to generate detectable light signals (such as reflected light, fluorescence, scattered light, etc.) in the sample.
Common types:
Continuous light sources, such as deuterium lamps (in the ultraviolet region), tungsten halogen lamps (in the visible near infrared region), xenon lamps (in the ultraviolet visible region), etc., are suitable for conventional absorption and reflection spectroscopy measurements.
Pulse light source: such as laser (with good monochromaticity), suitable for scenarios such as fluorescence and Raman spectroscopy that require specific wavelength excitation.
Auxiliary components: including light source stabilizer (ensuring stable light intensity), lens or fiber optic (guiding light to the sample or monochromator).
2、 Sample Room/Sample Pool
Function: Place the sample and achieve the interaction between light and the sample (such as absorption, reflection, transmission, scattering, etc.).
Design features:
Design different shelves based on sample morphology (solid, liquid, gas), for example, quartz colorimetric dishes are commonly used for liquid samples, while reflective probes or sample tables are used for solid samples.
Some instruments are equipped with constant temperature, stirring and other devices to meet the measurement needs of special samples (such as biological samples and chemical reaction systems).
3、 Spectral system (monochromator)
Function: Decompose composite light into monochromatic light arranged in wavelength order, which is one of the core components of the spectrometer.
Main components:
Incident slit: limits the width of incident light, reduces stray light, and improves spectral resolution.
Collimator mirror: converts divergent light passing through a slit into parallel light and projects it onto a dispersive element.
Dispersion element: realizes the dispersion (splitting) of light, common types include:
Grating: Using the principles of diffraction and interference of light to separate light, with high dispersion rate and wide wavelength range, it is the mainstream choice.
Prism: uses the principle of refraction of light to separate light, suitable for specific wavelength ranges (such as visible light), but with a low dispersion rate.
Focusing mirror: Focus the dispersed monochromatic light onto the exit slit or detector array.
4、 Detection system
Function: Convert optical signals (photons) into electrical signals (current or voltage) and perform preliminary amplification.
Core components:
Multi channel detector array: This is the key difference between multi-channel spectrometers and single channel spectrometers. It can simultaneously detect optical signals of multiple wavelengths without the need for moving parts to scan wavelengths, greatly improving detection speed. Common types include:
Charge Coupled Device (CCD): suitable for the UV visible region, with high sensitivity and fast response speed, widely used in conventional spectral analysis.
Photodiode array (PDA): Short response time, suitable for monitoring fast dynamic processes such as chemical reaction kinetics.
Infrared detector array (such as mercury cadmium telluride MCT array): suitable for the infrared spectral region, requiring refrigeration equipment to reduce noise.
Signal amplification circuit: amplifies the weak electrical signal output by the detector for subsequent processing.
5、 Data Processing and Control System
Function: To collect, convert, analyze electrical signals, and control the operation of various components of the instrument (such as light source switches, wavelength calibration, etc.).
form:
Data acquisition card: converts analog electrical signals into digital signals and transmits them to a computer.
Software system: Implement real-time display, storage, and analysis of spectral data (such as peak detection, baseline correction, spectral fitting, etc.), and provide instrument operation interface (parameter settings, method editing, etc.).
Control system: Coordinate the operation of the light source, spectral system, and detector through microprocessors or computer instructions to ensure stable operation of the instrument.