The following are the three major causes and solutions of malfunctions in fully automatic gas samplers:

Fault 1: Unstable injection volume

1. Cause of malfunction

Injection needle issue: The inner wall of the injection needle may be contaminated due to sample residue, resulting in poor circulation; The needle tip is prone to blockage or deformation, which affects the normal passage of liquids; The needle rod sealing gasket will gradually age over time, leading to a decrease in airtightness. These factors can all cause instability in the injection volume.

Abnormal operation of the injection pump: If the injection pump cannot maintain stability or leaks during operation, it will not be able to accurately deliver the sample, resulting in fluctuations in the injection volume.

2. Handling method

Cleaning and replacement of injection needles: Regularly clean the injection needles, rinse their inner walls with a suitable solvent (such as methanol), and remove attached impurities and residual samples. If slight deformations such as bending or burrs are found on the needle tip, a specialized needle corrector can be used for repair; If the deformation is severe, it is necessary to replace the injection needle with a new one in a timely manner. At the same time, attention should be paid to the condition of the sealing gasket at the connection between the needle rod and the injection valve. Once cracks or decreased elasticity occur, the same type of fluororubber or polytetrafluoroethylene sealing gasket should be replaced immediately.

Inspect and repair the sample pump: Carefully check the working status of the sample pump to ensure smooth operation and no leakage. If there is suspicion of a malfunction in the injection pump, consider replacing it with a new one to ensure the normal operation of the system.

Optimize the injection program: Reasonably adjust the injection speed and injection volume to maintain consistency, thereby reducing injection volume fluctuations caused by improper operation.

Fault 2: Leakage in the fully automatic gas sampler system

1. Cause of malfunction

Poor sealing of components: Seals in multiple parts of the system, such as valves and pipeline connections, may wear and age due to prolonged use, leading to a decrease in sealing performance and causing gas leakage.

Pipeline damage: Frequent use and external environmental influences may cause cracks, damages, and other issues in the pipeline, which is also one of the reasons for system leaks.

2. Handling method

Comprehensive leak detection: Use a professional leak detector to conduct a comprehensive and detailed inspection of the entire system, accurately locating the leak points.

Repair or replace components: Take corresponding repair measures for the discovered leakage points, such as tightening loose joints, replacing damaged sealing rings, etc. For components that have aged or been severely damaged, they should be replaced in a timely manner to ensure good sealing of the system.

Regular maintenance: Establish a sound regular maintenance system, strengthen inspection and maintenance of the system, and prevent potential leakage problems in advance.

Fault 3: Cross contamination of fully automatic gas sampler samples

1. Cause of malfunction

Poor cleaning of the injection needle: During continuous analysis and testing, if the injection needle is not cleaned thoroughly, the residual sample from the previous analysis will be mixed into the next analysis sample, resulting in cross contamination.

Sample bottle and bottle cap contamination: Reusing disposable sample bottles or adsorbing residues from previous samples on bottle cap spacers can be sources of cross contamination.

2. Handling method

Strengthen the cleaning of injection needles: optimize the cleaning program, increase the amount of cleaning solvent appropriately, and extend the cleaning time. Select the appropriate cleaning solvent based on the polarity of the sample, such as using a methanol water mixture for polar samples and a n-hexane isopropanol mixture for non-polar samples. In addition, a deep cleaning should be performed once a week by immersing the injection needle in a specialized cleaning solution and subjecting it to ultrasonic treatment for 15 minutes.

Standardize the use of sample bottles: strictly follow the operating procedures, use disposable polypropylene sample bottles, and avoid repeated cleaning and use. At the same time, use low adsorption fluoropolymer material bottle cap spacers and carefully inspect the spacers for damage or indentation after each injection. Before loading the sample bottle, blow the bottle mouth with nitrogen to effectively remove any residual samples that may adhere to the bottle mouth.