Composition of the industrial instrument
Industrial instrument generally consists of four parts:
1. Sampling and pretreatment system
The sampling and pretreatment system is an indispensable part to ensure the normal operation of the analyzer. Its function is to take representative analytical medium sample wells from the object for necessary pretreatment.
The sampling device shall include the sampling probe and other components directly related to the probe, such as a cooling and condensation collector, back flushing washer, suction device, and sampling pump. The main function of these components is to sample, and also conduct preliminary pretreatment of samples. For example, there are positive pressure sampling and negative pressure sampling. For negative pressure sampling, there should be a suction device. In addition, when sampling, the samples with a large amount of smoke and dust are often filtered with a water washing method for mechanical impurities and corrosive gases to preliminarily filter out the mechanical impurities with large particles in the samples. Since the sampling device is directly installed on the site, the working conditions are poor and it is easy to be damaged, so it should be made of good materials and easy to repair or replace at the same time.
After passing through the sampling probe, the sample is passed into the pretreatment system. This part includes a filter, dryer, precision pressure regulating valve, pressure stabilizing valve, flow stabilizing valve, various switching systems (such as switching between a sample and standard sample, multi-point sampling switching), diverter, flow indicator and flow regulator, various open and close valves and recovery systems.
These components are used to further pretreat the samples, mainly to filter out fine dust, chemically filter or absorb oil, corrosive substances, and water, and remove some interfering components. At the same time, the pressure, flow, and temperature of the sample shall be controlled to meet the requirements of the analytical instrument.
The detector (also called the transmitter and sensor) is the heart of the instrument. Its function is to convert the components or properties of the analyzed substance into electrical signals. Different analytical instruments have different detection forms, so there are different detectors.
3. Measurement and signal processing system
The function of this part is to further process the information provided by the detector, such as the conversion, amplification, linearization of electrical signals, conversion into unified signals (such as 4~20mA, 0~10mA current, etc.) and digital signals, and send the signals to the display device without distortion.
4. Display the device
Used to display analysis results. Generally, there are two kinds of analog display and digital display. Analog display instruments generally adopt general display instruments, such as moving coil display instruments or electronic potential difference calculation with records. These display instruments shall be re-scaled according to the composition of the tested substance. Now, the digital display is gradually used in analytical instruments, and image display is used in analytical instruments connected with computers.
Classification of the industrial instrument
Analytical instruments can be divided into two basic forms according to the place of use: laboratory analytical instruments and industrial analytical instruments. The former is used for qualitative and quantitative analysis in the laboratory, which generally gives relatively accurate results, usually manual sampling, and intermittent analysis. The latter is used in industrial processes, and can fully analyze automatically, that is, automatically sample, continuously analyze, and indicate or record the analysis results at any time. An industrial instrument is also called an online instrument or process instrument. Classified by the tested object: hydrogen instrument, oxygen analyzer, industrial PH meter, salt meter, etc; According to its working principle, it can also be divided into the following categories:(1) Electrochemical instrument (analyzer). Including conductivity instrument, potential analyzer, coulometric analyzer, ion concentration meter, galvanic cell analyzer, electrolytic analyzer, polarograph, etc.
(2) Thermal instrument. Including various thermal instrument, thermal conductivity analyzers, thermochemical analyzers, etc.
(3) Magnetic instrument. Including heated magnetic instrument, magnetic mechanical analyzer, magnetic gas analyzer, nuclear magnetic resonance, paramagnetic resonance spectrometer, etc.
(4) Optical instrument. Including emission spectrometer, infrared absorption type, infrared and ultraviolet analyzer, infrared spectrophotometer, ultraviolet and visible light photometer, spectrophotometer, atomic absorption spectrophotometer, optical interference analyzer, scattering analyzer, polarimeter, refractometer, photoelectric colorimetric analyzer, polarization analyzer, etc.
(5) X-ray analyzer instrument. Including an X-ray diffractometer, X-ray absorption analyzer, X-ray fluorescence analyzer, and y-ray analyzer.
(6) Chromatograph. Including gas chromatograph, liquid chromatograph, thin-layer chromatography, etc.
(7) Electronic and ionic optical analyzer instrument. Including electron probes, ion probes, electron potential meters, and various mass spectrometers.(8) Other analyzers. Analytical instruments not belonging to the above categories and those involving two or more categories of analytical principles.