1、 Daily operation standards
Pre-start inspection
Ensure that the instrument is placed on a stable and well ventilated horizontal platform, avoiding direct sunlight and strong magnetic field interference.
Check the pressure of the nitrogen cylinder (≥ 2MPa) and the instrument reaction pressure (0.5-0.9MPa), and confirm that there is no air leakage at the gas circuit joint.
Check the sealing of the adsorption tube to avoid a decrease in recovery rate due to carrier gas leakage.
Parameter Settings
Temperature setting: Set the primary resolution temperature (40-400 ℃, typical value 300 ℃), secondary resolution rate (>4500 ℃/min), and cold trap focusing temperature (-40 ℃ to -5 ℃) according to the properties of the sample.
Flow regulation: after connecting nitrogen, adjust the purge gas flow to a suitable value (such as 100ml/min) to ensure the stability of carrier gas.
Program settings: Input parameters such as heating/cooling rate and test temperature range through touch screen or buttons, and save the preset program for future use.
Sample processing and injection
Load the adsorption tube or solid sample for collecting VOCs into the injection position, and the sealed sample should be equilibrated to room temperature in advance.
Insert the adsorption tube into the quick plug, rotate the handle clockwise to ensure sealing, and start the desorption process after inserting it into the heating furnace (such as blowing for 3-5 minutes and desorption for 1 minute).
Experimental process monitoring
Real time observation of temperature, flow rate and other parameter changes to ensure that the instrument runs according to the preset program.
After the experiment is completed, start the automatic blowback program to clear the residual pipeline and avoid cross contamination.
2、 Common problem handling
The turntable is stuck
Reason: Mechanical failure, sensor malfunction, motor problem, or loose screws on the turntable shaft.
Solution: Immediately stop the machine and check if there are any foreign objects or mechanical damage in the turntable area; Use diagnostic functions to check the status of sensors and motors; Tighten the screws of the turntable shaft; If necessary, manually adjust the position of the turntable or contact professional maintenance.
Air leakage
Performance: Abnormal pressure value (such as pressure>30kPa in purging state).
Solution: Check if there is any air leakage in the air circuit joints and gaskets, and if the needle is blocked or broken; Repair or replace the leaking area.
Desorption failure or low recovery rate
Reason: Low or high desorption temperature, poor sealing of adsorption tube.
Solution: Optimize desorption temperature (typical value 300 ℃± 1 ℃); Check if the sealing ring of the adsorption tube is intact and ensure that the system is leak free.
The instrument cannot start or displays abnormally
Check: Confirm if the power plug is properly plugged in and if the fuse is blown; Check if the temperature measuring element (such as platinum resistor) is open or short circuited.
Solution: Replace fuses or temperature measuring components; If the problem persists, contact the manufacturer's technical support.
Poor focusing effect of cold trap
Reason: Improper temperature setting of the cold trap or malfunction of the refrigeration system.
Solution: Adjust the temperature of the cold trap to -40 ℃ to -5 ℃; Check if the refrigeration system is functioning properly and contact maintenance if necessary.
3、 Maintenance and upkeep
Regular leak detection: Use the "leak detection" function in idle state to check the pressure difference before and after 15 seconds (≤ 10kPa is normal).
Clean the pipeline: After the experiment, blow the pipeline with high-purity nitrogen to avoid residue accumulation.
Replace consumables: Regularly replace the adsorption tube, sealing ring, and air path filter to ensure stable instrument performance.
Environmental requirements: Maintain stable laboratory temperature (5-35 ℃) and humidity (≤ 85%), and avoid instrument moisture or overheating.