1XY series high-frequency infrared carbon sulfur analyzer infrared detection principle:

Gas molecules such as CO2 and SO2 have selective absorption spectra in the infrared wavelength range. When a specific wavelength of infrared light passes through CO2 or SO2 gas, it can produce strong light absorption. This absorption law can be derived from Lambert Beer's law.

IO(λ)=Ii(λ)(- α(λ)CL)…………………………(1)

Since the detector converts optical signals into electrical signals, when the detector operates in a linear region, (1) can be rewritten as:

VO(λ)=Vi(λ)(- α(λ)CL)…………………………(1)

In the formula, Ii (λ) and Vi (λ) represent the incident light intensity and corresponding electrical signal value at a specific wavelength λ, respectively.

IO (λ) and VO (λ) respectively represent the emitted light intensity and corresponding electrical signal value after passing through the absorption cell.

α (λ) is the absorption coefficient of a gas measured at a specific wavelength λ.

XY series high-frequency analysis cell optical path diagram

As can be seen from the above equation, when a specific wavelength is selected and the length of the analysis cell (absorption cell) is determined, the concentration of the measured gas in the mixed gas can be calculated by measuring the light intensity IO. This is the basic principle of infrared absorption method for quantitatively measuring gas concentration. The selected measurement wavelengths for this instrument are 4.26um for CO2 and 7.4um for SO2.

2、 XY series high-frequency infrared carbon sulfur analyzer high-frequency heating principle:

When a metal conductor is subjected to a high-frequency alternating electric field, according to Faraday's law of electromagnetic induction, an induced electromotive force will be generated inside the metal conductor. Due to the low resistance of the conductor, a strong induced current will be generated. According to Joule Lenz's law, an alternating magnetic field will cause the current in a conductor to flow towards the surface of the conductor, resulting in a skin effect. The density of the current between Shun and Shun is proportional to the frequency. The higher the frequency, the more severe the skin effect, resulting in a decrease in the effective conductive area and an increase in resistance, causing the conductor to rapidly heat up.

3、 Working principle of high-frequency induction circuit for XY series high-frequency infrared carbon sulfur analyzer:

Turn on the power switch on the panel, and the 220V AC voltage is divided into three paths through the power filter LB1 for the operation of the whole machine. One path is used through the filter LB2 for the operation of the axial fan F, one path is used for the operation of the filament transformer T2, and the other path is controlled by the solid-state relay K2 for the operation of the high-voltage circuit. When the high-frequency switch is turned on, the solid-state relay K2 is turned on, and the primary of the step-up transformer T1 is supplied with 220V AC voltage. The secondary outputs high voltage, which is rectified by the high voltage rectifier stacks V1-V4 to generate DC high voltage for the anode of the oscillation control. At this time, C3, C4, and L2 form an LC oscillation circuit, and combustion heating begins. By adjusting the gate potentiometer W, the gate current can be changed, thereby altering the negative feedback effect in the circuit. When the set combustion time is reached, the high-voltage power supply automatically shuts off and the combustion heating process ends. Refer to Figure ⑶ Electrical schematic diagram for details.

In addition, there is an overcurrent protection device in the circuit. Once the anode current exceeds 0.7A or the combustion time exceeds 1 minute, the circuit automatically cuts off the high-voltage power supply and alarms. After hearing the alarm sound, press the "Reset" switch on the panel to eliminate the alarm sound and restore the machine to its original working state. After processing, it can continue to work.

Figure ⑶ - Electrical schematic diagram

4、 Working principle of gas path for XY series high-frequency infrared carbon sulfur analyzer:

Figure ⑷ - Schematic diagram of gas circuit

Figure ⑷ shows the schematic diagram of the instrument's gas circuit. Oxygen is sent into the instrument through the pressure reducing valve at the upper end of the oxygen cylinder, with a regulated pressure of 0.18-0.2MPa, for combustion purposes. The power gas is generally nitrogen or compressed air for power purposes.

The power gas passes through the compression valve to compress the ash discharge pipe. The quartz tube is cleaned by the automatic cleaning device through the automatic cleaning valve, and the gas cylinder is lifted and lowered through the lifting valve.

The combustion gas is purified and dried by the purification furnace through the total oxygen valve, and then divided into two paths for instrument supply: one path is regulated by a 0-3 L/min flow meter to provide top blowing oxygen after a certain period of flow rate adjustment. When cleaning the filter screen, the cleaning valve is used for dust removal. The purpose of using a constant pressure regulator for the carrier gas is to maintain a constant pressure inside the combustion chamber. The mixed gas generated by heating and oxygen combustion of the sample is removed of dust by degreasing cotton and moisture by desiccant. It enters the sulfur tank through the inlet valve of the gas chamber, and then enters the carbon tank through a 0-5 L/min flow meter. After determining the actual flow rate through the 0-5 L/min flow meter, it is vented through the outlet valve of the gas chamber.

5、 Working principle of XY series high-frequency infrared carbon sulfur analyzer:

The working principle of the whole machine is shown in Figure ⑸,

It is divided into three parts: upper, middle, and lower. The upper part is the gas path system, and each arrow represents the direction of gas flow; The middle part is a dashed box, which reflects the entire process of converting the optical signal indicated by the arrow into an electrical signal in the gas analysis chamber; The lower part is the circuit control system.