First, the installation of the chromatograph 1. Requirements for the gas chromatograph analysis chamber (1) There must be no strong magnetic fields, flammable or corrosive gases around the analysis chamber. (2) The indoor ambient temperature should be in the range of 5 to 35 degrees, the humidity should be less than or equal to 80% (relative humidity), and air circulation should be maintained indoors. It is best to install air conditioners in conditional factories. (3) Prepare a working platform that can withstand the entire instrument, moderate width and easy operation. The general factory is better with cement platform (0.6~0.8 m high), the platform can't be close to the wall, and should be 0.8~1.0 m away from the wall, which is convenient for wiring and maintenance. (4) The power line capacity for the instrument should be above 3KVA, and the power supply of the instrument should not be shared with the high-power power consumption equipment or the power equipment that frequently changes greatly. The power supply must be well grounded. Generally, the copper rod (wire) with a length of about 0.5~1.0 m is nailed on the wet ground (or the salt solution), and then the power grounding point is connected with it. In general, the grounding resistance is less than 1 ohm. (Note: It is recommended that the power supply and the case are grounded for better results). 2. Gas source preparation and purification (1) Gas source preparation High-pressure cylinders (usually available in large and medium-sized cities) that require gas are prepared in advance. Zhuang’s gas cylinder can only contain this gas, and the color of each cylinder Represents a gas that cannot be interchanged. Generally, three gases of nitrogen, hydrogen and air are used, and it is preferable to prepare two cylinders for each gas for use. Some plants use hydrogen generators and air compressors, but air compressors must be oil-free. When the cylinder pressure drops to 1~2Mpa, the cylinder should be replaced. Generally, the manufacturer can use 99.99% of the above gas, and the electron capture detector must use a high purity gas source of 99.999% or more. (2) Gas source purification In order to get rid of the moisture, ash and organic gas components that may be contained in various gases, the gas should be strictly cleaned before entering the instrument. If all the cylinder gas is used, some chromatographs are equipped with a purifier, and the inside is filled with 5A molecular sieve, activated carbon, silica gel, which can basically meet the requirements. If a general hydrogen generator is used, the water purification treatment must be strengthened, so the drying pipe area should be increased (the volume is more than 450 cubic centimeters, the filler is preferably 5A molecular sieve), and the volume after the generator is larger. The reservoir barrel reduces or overcomes the effects on the instrument baseline when the source pressure fluctuates. If an air compressor is used as the air source, the air inlet of the air compressor should be reinforced with air filtration, and the volume of the purification pipe should be increased. Half of the 5A molecular sieve and half of the activated carbon should be filled in the drying pipe. Generally, domestic oil-free gas compressors can meet the needs. 3. After the gas chromatograph completes the inspection and the instrument is unpacked, according to the list of accessories in the kit, the items are inspected item by item, and the spare parts of the vulnerable parts are properly preserved. Then, according to the instructions of the instrument's instruction manual, place it on the working platform, connect the parts of the instrument to the wiring diagram and each plug, and finally connect the chromatographic workstation or data processor. Be careful not to connect the connectors. 4. Connection of the external air circuit (1) The installation of the pressure reducing valve is equipped with a pressure reducing valve, if not, it is purchased. Two oxygen and one hydrogen pressure reducing valve were used. Install 2 oxygen pressure reducing valves and 1 hydrogen pressure reducing valve on the nitrogen, air and hydrogen cylinders (note that the hydrogen pressure reducing valve threads are reversed and the attached O-shaped plastic gasket is added at the interface. In order to seal), after tightening the nut, close the pressure reducing valve adjustment handle (ie, loosen) and open the cylinder high pressure valve. At this time, the pressure gauge high pressure gauge should have an indication. After the high pressure valve is closed, the indicated pressure should not drop. Otherwise, there is leakage, it should be eliminated in time (with gasket or raw material tape seal), sometimes the high pressure valve will leak, pay attention. Then turn the adjustment handle to drain the remaining air. (2) The external gas path connection method introduces the gas in the cylinder into the chromatograph, some use stainless steel tubes (φ2×0.5mm), and some use pressure-resistant plastic tubes (φ3×0.5mm). Plastic tubes are easy to handle, so plastic tubes are generally used. If a plastic tube is used, a stainless steel liner (φ2×20 mm) and some plastics for sealing should be used at the joint. The length of the plastic tube from the cylinder to the instrument is determined as needed. It should not be too long, and then the gas source and the instrument (gas inlet) are connected by a plastic tube. (3) Leak detection of the external gas path Upload the gas on the main gas path panel, shut off the valve knob of hydrogen and air, then open the high pressure valve of each cylinder, adjust the output pressure of the low pressure gauge on the pressure reducing valve, and make the carrier gas and air pressure It is 0.3~0.4Mpa and the hydrogen pressure is 0.2~0.25Mpa. Then close the high pressure valve. At this time, the indication value of the low pressure gauge on the pressure reducing valve should not be lowered. If it is lowered, it indicates that there is a leak in the connecting gas path and should be excluded. 5. Gas chromatographic inspection of gas chromatograph is a very important task. If there is leakage in the gas path, it will not only directly lead to unstable or weak sensitivity of the instrument, but also danger of explosion, so before operation This work must be carried out (the airtight inspection is generally to check the carrier airflow path, and the hydrogen and air flow paths may not be checked if they have not been removed). The method is to open the column cover, remove the column from the detector, block the column, and then open the carrier flow path, adjust the low-pressure output pressure to 0.3~0.4Mpa, and open the carrier gas knob on the host panel. The pressure gauge should have instructions. Finally, the carrier gas knob is turned off, and the pressure indication value before the column should not decrease within half an hour. If there is a decrease, there is a leak, which should be excluded. If there is leakage in the air circuit in the main unit, remove the side plate of the main unit and use soapy water (preferably sodium dodecyl sulfate solution) to check leaks one by one (hydrogen, air can also be leak tested), and finally soap Dry the water. Second, the commissioning of the instrument, the gas path, the instrument, etc. are connected according to the above, after the placement, the following inspection and debugging work can be carried out. 1. Before checking the instrument, the instrument should first turn on the carrier airflow path and adjust the carrier gas knob on the main unit panel (ie: carrier gas steady flow valve). (1) Start the main unit to turn on the main power switch of the main unit. The motor in the column box starts to work and check if there is any abnormal sound. If it is, immediately cut off the power and further check it out. Some chromatographs start self-diagnosis, indicating the operation of the instrument: normal or abnormal, abnormal display including which part has a problem, wiring error, and so on. (2) Each temperature control inspection according to the instructions, one by one for the column temperature (including temperature programming), the temperature of the injector (vaporization chamber), the temperature of the detector is checked at a constant temperature, whether it can be kept constant at high, medium and low temperatures, In particular, the column temperature and temperature control accuracy is required to reach 0.01 degrees. Plastic Net,Plastic Netting for Garden,Plastic Trellis Net,Plastic Net Fencing COFCO HEBEI INTERNATIONAL TRADING CO., LTD. , https://www.cofcohb.com