1. The mine rescue team applied the SP-2307 gas chromatograph as the main technical equipment for gas testing. This procedure is specifically developed for the laboratory technician to properly operate the SP-2307 gas chromatograph to provide correct gas analysis data for mine rescue teams handling accidents. 2. The laboratory technician should be specially trained to have a certain knowledge of gas testing and understand the structure and performance of the gas chromatograph before performing laboratory analysis. 3. The operator should strictly operate in accordance with the provisions of this regulation, and do routine maintenance, so that the instrument is always in good working condition, and can guarantee the testing task at any time. 4. Check the thermal conductive bridge. Open the rear panel of the analysis host and observe the grade of the terminal block. The five terminals between the 23th and 27th are the lead collection points of the thermal conductivity cell. Use a multimeter to measure the resistance between every 2 points, which should be 50 ohms. Use a 500 volt megger to measure the insulation resistance of the thermal conductive element to ground greater than 5 megohms.

5. Check the hydrogen flame evaluator. Uncover the main unit cover of the analysis unit, gently remove the evaluator cover, and check the collector and polarization insulation resistance with a 500 volt megohm meter, which should be infinite. 6. Check the polarization voltage and ignition voltage. Turn on the micro current amplifier power supply, put "polarity selection" in the "zero point" file, and measure the polarization voltage with a multimeter, it should be equal to zero. When placing "polarity selection" in "I-II+". or "I+II-", measure the polarization voltage with a multimeter to be +250 volts or -250 volts. Press on the micro-current amplifier panel. When the ignition button is pressed, observe that the ignition coil is red, which means normal. 7. Check the air tightness. Open the carrier gas high pressure cylinder switch, adjust the decompression table to make the outlet pressure reach 0.3 MPa. Adjust the main pressure regulator to make the pressure reach 0.2. MPa, adjust the needle valve to make the carrier gas flow rate reach 30 ml / min. Remove the connecting pipe at the outlet of the conversion column, close the outlet with a plug nut, close the carrier gas pressure regulator, cut off the gas source, observe the panel pressure Table, the pressure drop does not exceed 0.01 MPa in half an hour. Then connect the outlet of the conversion column to the hydrogen flame identifier, pass the carrier gas under the pressure of 0.2 MPa, and check the external joints of the hydrogen flame detector with soap liquid, if not When soap bubbles appear, it is considered to be airtight. 8. Connect the power cord. The three electrical control boxes are equipped with their own power cables, which are plugged into the corresponding power sockets and should meet their respective rated currents. The recorder power cord is Connect the phase line (ie the live wire) to the terminal marked with 220 volts, the center line On the terminal marked with “0”. 9. Connect the signal cable. Connect the three electrical control boxes to the main unit with the corresponding connecting wires. The signal input terminal on the back of the recorder is marked with “+”. - "and "p", the thermal conduction and hydrogen flame signal output lines should be connected to the two "+" and "-" terminals respectively. The "p" line terminal should be idle and not allowed to be connected to the shielded line.

10. Thermal conductivity is zero. Firstly, the carrier gas flow rate is stabilized at 30 ml/min. The “current adjustment” knob on the thermal power supply control box is adjusted to the lowest position, and the output attenuation is set to 1/32, and the thermal conductivity and recorder power is turned on. Record the zero adjustment potentiometer so that the recorder pointer is within the measurement range, such as at 1 millivolt. When hydrogen is used as the carrier gas, adjust the “Current Regulation” knob to add the thermal conductivity bridge to 200 mA. When the selector knob is placed in “Hot Guide Zero”, place the pool balance potentiometer in the middle position, and then adjust the “zero” point with the “thick”, “medium” and “fine” zero potentiometer recorder. When the selector knob is placed in “recording zero”, the “recording zero” potentiometer can be adjusted to select the baseline position of the instrument. When the selector knob is placed in the “measurement” position, the measurement can be started. The "measurement" position determines the polarity of the output signal. 11. Thermal conductivity cell balance. First add 200 mA to the bridge, set the selector knob to the “Measure” position, and twist the “Current Adjustment” knob to reduce the bridge current by 20 mA, from 200 mA to 180 mA. Observe the recorder pointer. Offset, use the "pool balance" knob to return the pointer to its original value. Then use the “current adjustment” knob to raise the bridge current by 20 mA, that is, return to 200 mA, observe the offset of the recorder pointer, and the three potentiometers of “thick”, “medium” and “thin” by the zero adjustment knob. Adjust the offset pointer back to the original value. Repeat the cycle until the current is reduced to 20 mA. When the attenuation is 1, the pointer of the recorder does not exceed ±1% of the full scale. 12. The hydrogen flame is not ignited and zeroed. Turn on the micro current amplifier power supply and place the “polarity selection” in the “I+II-” block. Set the Polarity selection band switch to Zero and the Attenuation band switch to 1. The "Base Flow Compensation" potentiometer is turned left to the head to the zero position. Select the band switch and put it in "Zoom in and zero". Turn on the recorder. After the pointer of the recorder is stable, use the “coarse adjustment” and “fine adjustment” potentiometers of “amplify and zero” to adjust the recorder to the zero position of 0 millivolts. Select the band switch to place the “record zero” and adjust the “record zero” knob to keep the recorder pointer in any position, usually at 1 mV. When the selected band switch is placed in the “measurement” position, the recorder pointer will remain at the 1 mV position at the “record zero”, indicating correct operation.

13. The hydrogen flame is ignited and zeroed. Nitrogen gas was supplied to the instrument main unit at a flow rate of 35 ml/min and an air flow rate of 600 ml/min. When the hydrogen flame evaluator is ignited, press the "Ignition" button on the micro-current amplifier panel for a maximum of 5 seconds, and the baseline will shift when the hydrogen flame is ignited. Place the “Polarity Selection” band switch on “Detection I+II-” and select the band switch to “Amplify and Zero”. Due to the influence of the base flow, the recorder pointer will be offset. Compensate the potentiometer and turn the recorder pointer back to zero. Select the band switch to be set to “Measure”. If the base stream is fully compensated, the recorder pointer will stop at the “recording zero” position when the ignition is not ignited. After the baseline is stabilized, the analysis can be performed. 14. Operating conditions. When conducting mine gas analysis, the operating conditions should generally meet the following requirements. Column 1: φ4 × 0.5, 1.5 m, 5A molecular sieve 60 ~ 80 mesh; column 2: φ 3 × 0.3, 1 m, TDX-0140 ~ 60 mesh; column temperature: 50 ° C; thermal conductivity bridge current: 200 mA; Detection chamber temperature: 120 ° C; reformer temperature: 360 ° C; column pressure: 0.19 MPa to 0.2 MPa; carrier gas flow: 42 ml / min; air flow: 600 ml / min; nitrogen flow: 34 ml / min Injection volume: 1 ml; recorder paper speed: 300 mm / hour. 15. Quantitative methods. When quantitating by chromatographic analysis, peak area and peak height are usually quantified. The peak area is obtained by multiplying the peak height by the half width, and the peak height and peak width can be measured by a triangular plate. The most commonly used quantitative methods in mine gas analysis are normalized quantitative method and external standard quantitative method. 16. Normalized quantitative method. When applying the normalized quantification method, each component is required to be separated, and the peak area can be measured. For components that do not require quantification, the area is also measured and the correction factor is known. In the calculation, the peak height can also be used instead of the peak area. If the correction factors of the components are similar or the same, the area normalization can be directly used for calculation. The calculation formula for the corrected area normalized quantitative method is as follows: 17. Standard curve quantification method. Under certain operating conditions, a standard gas sample of different content is prepared by using a pure gas of a known concentration and using air or nitrogen as a base gas. At the calibration time, a certain volume of standard gas sample is injected into the chromatograph, and the peak height or peak area is used as a standard curve for the standard gas sample. In the formal analysis, the operating conditions of the chromatograph are stabilized in the state of the standard curve, so that the sample to be tested is also injected with the same injection amount, and the peak height or peak area is measured on the recorder, from the standard curve. The percentage of the measured component, or ppm (parts per million), is found on the coordinates. 18. Compare calculations to quantify. At each analysis, a standard gas sample of known content is injected into the chromatograph, and the peak height or peak area is measured on the recorder as a basis for calculation. Re-injection of the gas sample to be measured, the peak area or peak height measured from the recorder, and the calculation formula can be substituted to obtain the content of each component in the gas sample to be tested.

19. Formal analysis. For analysis, a six-way valve can be used to inject the sample or in the injector. When analyzing the mine gas, it is necessary to inject two injection ports in two injections. The first time was injected from the left (first) inlet, and the 5A molecular sieve column separated O2, N2, CH4 and CO, and the chromatographic peak generated by the thermal conductivity cell on the recorder was measured. When the sample is injected from the second inlet, the gas sample is separated from the CO, CH4 and CO2 by the TDX-01 column, and the corresponding signal is generated by the hydrogen flame detector. The peak value of the chromatogram is measured on the recorder, and the standard curve method can be applied. The comparative calculation method is used to calculate the analysis results of each component. The first injection port injection sample is a constant analysis of each component having a content of 0.1% or more. The second injection port is mainly used for the analysis of trace carbon monoxide, and for methane and carbon dioxide, constant analysis can be performed at this inlet. 20. Power off. After the analysis is finished, the power of the recorder is turned off, and then the power supply of the thermostat controller, the micro current amplifier, and the thermal power source controller are sequentially cut off. 21. Cool down. After the power is turned off, the main unit cover is opened to cool the heating unit rapidly. The temperature of each point is continuously observed by the temperature measurement millivoltmeter, and the temperature of the reformer is mainly paid attention to. 22. Shut down. When the hydrogen flame detector is stopped, the air and nitrogen sources should be turned off immediately. The carrier gas flow rate remains unchanged. When the temperature of each point of the chromatograph drops to near room temperature, the carrier gas source can be turned off and the instrument can be restored to the initial normal state. 23. When leaking, ventilate and deflate slowly to avoid damaging the thermal conductive elements or impacting the packing in the column. 24. When starting the instrument, it is necessary to pass the carrier gas for 5 minutes, then add the bridge current and then heat up to avoid burning the thermal conductivity cell components and the nickel catalyst. For the first installation of the instrument, the carrier gas must be supplied with the carrier gas for 20 minutes. 25. When shutting down, it must be ensured that the nickel catalyst continuously passes through the hydrogen gas, and the flow rate is not less than 20 ml/min. When the temperature of the reformer is lowered to room temperature, the gas source can be turned off. 26. When opening the cover of the hydrogen flame detector, Place the amplifier "polarity selection" in the "zero point" block to prevent the polarization ring from hitting the ground and burning the micro current amplifier. 27. Do not exceed the rated current when powering the thermal conductivity cell bridge. When hydrogen is used as the carrier gas, the bridge flow must not exceed 250 mA. When nitrogen or argon is used as the carrier gas, the maximum is not more than 150 mA. Excessive current can easily damage the thermal conductive components or reduce component life. 28. After a period of use, if it is found that the silica gel and caustic asbestos in the transparent filter tube have failed, the new agent should be replaced immediately.

Speed Clamp

The fastest-adjusting frame clamp on the market.

Completely knurled for good grip, the speed-clamping nuts are designed to let you make fast adjustments, yet hold securely when you tighten them. They are cross drilled to slide easily on the rods until they come up against a corner clamp; then their threads engage. To release them, you just have to back them off a turn or two and they are then free sliding again.

Professional Speed Clamp,Industrial Clamps,Pipe Clamps,Heavy Duty Quick Release Clamps

Ningbo Gemu Ventilation Technology Compnay Limited , https://www.golmacool.com