In the process of using the gas chromatograph, the operator often encounters the problem of fault maintenance of the gas chromatograph. In this paper, the main gas chromatograph is used for simple analysis when the instrument is not properly started and the temperature control is abnormal. Ungrouped,High Quality Ungrouped,Ungrouped Details, CN Jining Juheng Hydraulic Machinery Co., Ltd. , https://www.juheng-cn.com
Gas chromatograph maintenance points (1)
Foundation: The basis for checking and finding the cause of the fault is to master the method of fault identification. The basis for mastering the fault identification method is to familiarize with and understand the composition, function, and working principle of each part of the instrument.
â—‡Inputs and outputs: Usually every part, part, or even part of the instrument has its input and output. The input generally refers to the premise that the part works normally. The output generally refers to the function or function of the part.
For example: FID amplifier, its input is the micro-current signal transmitted by the FID detector through the ion signal line, the working power of the amplifier, and the zero-potentiometer of the amplifier. Its output is amplified and sent to the secondary instrument. Electrical signal. The method for judging whether the FID amplifier is working properly is: A. If the input is normal and the output is not normal, the amplifier is faulty. B. If the input and output are normal, the amplifier is normal. C. If the input is not normal, the amplifier is normal and cannot be determined.
â—‡Collection and accumulation: Actively collect, carefully record, and continuously accumulate various methods for judging the normal operation of each part of the instrument, and understand, familiarize, master, and keep in mind these fault identification methods.
â–²The instrument is not starting properly.
After the power is turned on, the instrument does not respond or the initialization is abnormal.
§ A. Shut down and unplug the power cord to check if the grid voltage and grounding wire are normal.
§ B. Use a multimeter to check that the main unit fuse, transformer and its connectors, power switch and its connections, and other cables are normal.
§ C. Plug in the power plug and turn it on again to see if the instrument is normal.
§ D. If the startup is normal and the initialization is not normal, follow the prompts to check accordingly.
§ E. If the motor is running normally and the display is not normal, check if the keyboard/display section is normal.
§ F. If the display is normal and the motor is not working properly, check if the motor, its transformer, fuse, etc. are normal.
§ G. If necessary, unplug some components that are not related to initialization and observe them.
§ H. If the initialization is still not normal, it is basically determined that the microcomputer board is faulty.
â–² Temperature control is not normal.
The fingers do not heat up or the temperature is unstable.
§ A. When all temperatures are abnormal, first check if the grid voltage and grounding wire are normal.
§ B. When all temperatures are unstable, reduce the oven temperature and observe the temperature of the injector and detector. If it is normal, it is the fault caused by the grid voltage or grounding wire.
§ C. If the grid voltage and grounding wire are normal, it is usually a micro-board failure. Generally speaking, the possibility of simultaneous damage of the platinum-controlled or heating wires of each temperature control is extremely low.
§ D. If the temperature control of a certain channel is not normal, check whether the platinum resistance of the temperature control and the heating wire are normal.
§ E. If the temperature control of the oven is not normal, check whether the corresponding relay and thyristor are normal.
§ F. If the platinum resistance, heating wire, etc. are normal, the microcomputer board is faulty.
§ G. During the above inspection process, pay attention to whether the connectors and connecting wires of each component have open circuit, short circuit, and poor contact.
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Gas chromatograph maintenance points (1)