Container sampling

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If an offline liquid particle counter configured in the laboratory is used, using a sampling container to collect liquid samples from the site for detection is the only method. Container sampling is mainly carried out according to the following procedures:

1) Before sampling, ensure that the pollutants in the fluid system are in a suspended state;

2) Clean the sampling area and sampling valve, and prepare for sampling;

3) Fill in the sampling container label;

4) Adjust the sampling valve and release the working fluid at the blind end when there is pressure in the sampling pipeline;

5) Sample without changing the opening position of the sampling valve until the liquid level reaches the marked line of the sampling container or the required sampling volume, then quickly move the sampling container, close the sampling valve, and seal the sampling container;

6) Restore the original state of the system and end the sampling process.

To collect a representative liquid sample, it is necessary to follow the above six steps carefully, and none of them should be omitted.

Online sampling

Online detection does not have to worry about secondary pollution caused by sampling containers and sampling. The fluid system liquid sample is directly measured by the particle sensor through the flow controller, and the oil pollution level is directly displayed. Another advantage is that the system pollution level can be continuously measured multiple times at any interval, thus obtaining the pollution level of the fluid system at different time periods. The online monitoring program is as follows:

1) Before sampling, ensure that the pollutants in the fluid system are in a suspended state;

2) Clean the sampling area and sampling valve, connect the online flow control device and liquid particle counter;

3) Check the working pressure at the outlet of the sampling valve, which should be within the working pressure range of the liquid particle counter. If it exceeds this range, a pressure reducing device should be used (the pressure reducing device will not change the distribution of particles);

4) Adjust the sampling valve and online flow control device under pressure in the sampling pipeline to meet the flow requirements of the particle sensor;

5) Perform online measurement according to the usage method of particle counter;

6) After the online measurement is completed, close the sampling valve, remove the online flow control device and particle counter;

7) Restore the original state of the system and end the sampling process.

Precautions for Sampling System Pipelines

1) All operations that are prone to causing secondary pollution should be prohibited, such as contact between the sampling container mouth and hands or sampling valves, random storage of the sampling container cover, and the use of easily detachable fiber cloths for wiping;

2) During sampling, adverse environments such as wind, dust, rain, snow, and fog should be avoided;

3) When using a container to collect liquid samples, it is important to note that the sampling volume must not exceed the marked line of the container. If it exceeds the specified volume, it is considered a waste sample (before testing, the liquid sample needs to be vigorously shaken to ensure uniform particle distribution. If the sampling volume is too large, it will be impossible to reprocess the liquid sample; if part of the sample is poured out due to shaking, it will change the particle contamination concentration of the liquid sample).