A chave para a precisão do detector de vazamento do espectrômetro de massa de hélio: o papel e a importância do vazamento padrão externo

The external standard leak is a standard used to test the accuracy of the detector de vazamento de espectrômetro de massa de hélio. The detector de vazamento de espectrômetro de massa de hélio is a comparative test instrument that ionizes the helium molecules entering the mass spectrometer chamber and determines the number of helium molecules by amplifying the current. Since the proportion and electrical parameters of the helium molecules entering the mass spectrometer chamber may be different, the leak rate may be different even if the current is the same; or the leak rate may be the same but the current may be different. Therefore, the leak detector itself does not know what the leak rate corresponds to the amplified current, and a reference is needed, which is the standard leak.

When using a helium standard leak to calibrate a helium mass spectrometer leak detector, first set the calibration value inside the helium mass spectrometer leak detector to be the same as the actual leak rate value of the standard leak, then calibrate according to the calibration procedure and save the calibration result. In addition, when the leak detector is in sniffing mode, you can bring the sniffing gun close to the leak point of the calibration leak, compare the difference between the measured value on the helium mass spectrometer leak detector and the actual value of the standard leak, then calibrate and compare again.

Many users have a misunderstanding when using helium mass spectrometer leak detectors, thinking that as long as the leak detector can pass the self-test, it means that the helium mass spectrometer leak detector is working properly. But this is not the case. If the leak detector can pass the self-test, it only means that there is basically no problem with the leak detector itself, but it cannot determine whether the leak detector is accurate.

Helium mass spectrometer leak detectors are widely used in various fields. With the advancement of science and technology and the improvement of production processes, the performance requirements for helium mass spectrometer leak detectors are getting higher and higher. Therefore, it is very important to ensure the accuracy of helium mass spectrometer leak detectors. In order to ensure the accuracy of the test results of helium mass spectrometer leak detectors, it is necessary to ensure the accuracy of the built-in standard leak hole.

To ensure the accuracy of the built-in standard leak, there are several suggestions:

The standard leak itself must meet the relevant quality requirements and be able to provide a third-party test certificate.

The standard leak should be checked and calibrated regularly. It is recommended to calibrate it once a year. In particular, standard leaks with large annual leakage rates need to be calibrated more frequently. If an abnormality is found, an external leak can be used for calibration.

Pay attention to the use environment. The production and testing of standard leaks should be carried out at room temperature of 20-25℃. Some standard leaks are particularly sensitive to temperature. For every 1℃ change, the leak rate may have an error of more than 3%.

In summary, in order to use the helium mass spectrometer leak detector correctly and improve its accuracy, it is necessary to use the standard leak hole correctly. The fact that the helium mass spectrometer leak detector can pass the self-test only means that there is basically no problem with the leak detector itself, but it cannot determine its accuracy. The accuracy of the final test result depends on the built-in standard leak hole. The standard leak hole has a known size and leakage rate, and can be used as a reference to verify the accuracy and sensitivity of the leak detector.

Regular calibration with a standard leak can ensure that the leak detector can accurately detect tiny gas leaks in actual applications and improve the reliability of detection.

The steps for using the standard leak hole of the helium mass spectrometer leak detector are as follows:

Prepare a standard leak: Standard leaks are usually provided by the manufacturer. They are small holes of known size and known leakage rate. Make sure the standard leak is clean and free of any impurities or blockages.

Connect the standard leak: Connect the standard leak to the adapter or interface of the helium mass spectrometer leak detector. Make sure the connection is tight and there are no gas leaks.

Set detection parameters: According to the specifications of the standard leak, set the detection parameters of the helium mass spectrometer leak detector, such as pressure range, flow rate, etc.

Start testing: Turn on the helium source and the leak detector, and allow helium to enter the system under test through the standard leak. The testing instrument will monitor helium leakage and display the leak rate.

Compare the results: Compare the detected leak rate with the known leak rate of the standard leak. If the test result matches the leak rate of the standard leak, it means that the leak detector is working properly.

When using, please pay attention to the following points:

Cleaning and maintenance: Make sure the standard leak is clean and free of any impurities or blockages. Clean the standard leak regularly to avoid contamination or blockage that may affect the performance of the leak.

Correct connection: Connect the standard leak correctly to the adapter or interface of the helium mass spectrometer leak detector. Make sure the connection is tight and there is no gas leakage.

Detection parameter setting: According to the specifications of the standard leak, correctly set the detection parameters of the helium mass spectrometer leak detector, such as pressure range, flow rate, etc. Make sure the parameter settings match the standard leak.

Environmental conditions: When using a standard leak for testing, ensure that the environmental conditions are stable. Avoid wind, airflow or other interference that may affect the test results.

Regular calibration: Regularly calibrate with a standard leak to ensure the accuracy and reliability of the leak detector. Establish an appropriate calibration frequency based on actual conditions and requirements.

Follow the operating instructions: Strictly follow the operating instructions of the helium mass spectrometer leak detector and the standard leak. Follow the instructions and safety precautions to ensure correct and safe operation.

Please note that the above are only general usage precautions. When using the standard leak, you need to refer to the detailed instructions and requirements of the helium mass spectrometer leak detector and the standard leak.