After completing all production processes, the casting products manufacturer’s steel products must be inspected and qualified by the manufacturing party, and the design party, the customer party, and a third-party inspection agency representing the customer shall be invited to jointly conduct on-site acceptance. The physical and chemical properties, non-destructive testing, and dimensional testing of the casting products manufacturer’s steel products shall be retested, and the engineering quality shall be confirmed in writing according to relevant standards.
With the deepening development of trade internationalization, representatives from all parties involved in re inspection often need to cross different regions or countries to come to the inspection site of the manufacturer, which brings additional costs and inconvenience to the project team due to waiting time and travel costs. Since the outbreak of the COVID-19, the impact of epidemic prevention control on inspection activities has become more significant. In many cases, customer representatives cannot arrive at the manufacturer’s site, so the remote witness method for on-site inspection came into being.
Propose a remote witnessing operation method for on-site inspection, which uses terminals such as mobile phones, cameras, or computers with high-definition camera functions and wireless network cards, equipped with internationally popular video conferencing software, to conduct real-time online witnessing inspection and acceptance under 5G wireless network coverage.
1. Preparation for remote witnessing work
According to the inspection plan approved by the client, at least 7 days before the workpiece reaches the witnessing or acceptance status, an inspection invitation shall be sent to all parties involved in the inspection to confirm their acceptance of the remote witnessing method and their ability to participate as scheduled. Adjustments may be made according to the schedule of the client and their representatives. An email link for remote witnessing shall be established according to the confirmed schedule and sent to the inspection representatives of all parties who need to participate.
Using Microsoft’s Teams software as an example, establish an email link and send the meeting link email to the client. For computers, the client can directly join the meeting using a browser without downloading the Teams software. For mobile phones or PAD terminals, it is necessary to download and register Teams software in advance. There are two ways to join the meeting: Method 1: After receiving the email link, click on the link in the email and join the meeting through Teams software; Method 2: Copy the conference link URL, paste it into the terminal browser software, and click “Join Conference”.
Notify all departments of the manufacturing party to prepare for inspection and ensure that the workpiece reaches the inspection status before the witness date.
2. Remote witnessing equipment and on-site layout
2.1 Remote Witness Site Conditions
The remote witness site should have the following conditions: sufficient lighting, high visibility, no dust, smoke and other pollutants in the ambient air, and the camera should be able to clearly capture the surface condition of the workpiece and inspect the operation process; There is no excessive noise pollution, and communication such as voice calls is required during the inspection process to ensure that the speech can be clearly recognized; The homework area achieves 5G network coverage, and there is no lag phenomenon during video conference testing.
2.2 On site witness camera equipment
Determine the number of camera equipment according to the requirements of the inspection items. Multiple camera equipment should be shared simultaneously, and the more equipment there is, the more detailed the recorded information. The camera equipment has a wireless network card, which can access the Internet to capture video and share it in real time. Usually, at least two camera devices are required, one is a close-up camera, used to record local close-up shots, observe the inspector’s operational details, and inspect the display screen of the equipment; Another is a long-range camera, used to record the overall layout of the inspection site, display the overall characteristics of the workpiece, observe and identify the relative position of the inspector and the workpiece. If conditions permit and it is necessary, more camera devices can be connected, as shown in Figure.
2.3 Inspection items applicable to remote witnessing
The inspection items suitable for remote witnessing include block cutting and steel stamp identification, size testing, ultrasonic testing, liquid penetration testing, hardness testing, roughness testing, chemical composition testing, mechanical performance testing (tensile testing and impact testing, etc.).
For magnetic particle testing, fluorescence method needs to be carried out in a dark room environment, and the camera cannot capture the inspection process clearly. Therefore, remote witnessing only recommends non fluorescence method.
3. Precautions for remote witnessing
3.1 Precautions for operators
The close-up camera operator needs to interpret in advance the key inspection content of the customer’s casting products manufacturer’s steel castings. For the key inspection content, the camera’s movement speed should be slow to ensure the accuracy of the customer’s observation of the key inspection content. The operator needs to first inspect the tools, documents, qualifications, etc. according to the inspection process, and can only proceed with the inspection of the casting products manufacturers steel parts after confirmation by the customer.
3.2 Precautions during the witnessing process
For questions raised by customers during the witnessing process regarding inspection content that has not been observed clearly or doubts about the inspection process of cast steel parts by casting products manufacturers, the inspection should be immediately suspended during the answering process, and the already inspected parts should be marked. Only after re observing and checking or explaining the problem clearly can the marked content be continued to be inspected. For unexpected situations, such as network issues or suspension of inspection caused by the lifting of steel castings by casting products manufacturers, it is necessary to immediately explain to the customer and continue to complete the inspection after the emergency situation ends.
4. Advantages, disadvantages, and development space of remote witnessing
4.1 Advantages of remote witnessing
(1) The inspection schedule is more flexible. For foreign customers, traditional on-site witnessing takes into account the itinerary of their travel and visits, usually requiring 14 days or even longer notice to attend the witness. The evaluation of the witness date is difficult to accurately assess, and once there are changes in production progress, it is difficult to adjust it in a timely manner. Remote witnessing ensures that customers do not leave their homes to participate in remote video witnessing. Customers are notified within one week in advance to arrange sufficient preparation work, and the evaluation of witness dates is more accurate. During the inspection, screen recordings or screenshots can be taken for evidence collection to retain evidence and facilitate communication with the manufacturing party.
(2) Save inspection costs. For manufacturers, remote witnessing provides a mechanism for co inspection with customers, reducing the cost of inspection preparation and repeated inspections. For intermediate process inspections such as machine tool processing, reducing waiting time significantly saves machine tool resources. For the designers, clients, and their representatives who participated in the inspection, travel expenses were avoided.
(3) Avoid travel restrictions. The parties participating in the witness may be far apart, especially in special environments similar to epidemic prevention and control. Travel restrictions may prevent smooth acceptance. The online inspection provided by remote witness provides a reliable and efficient solution.
4.2 Limitations of remote witnessing
(1) For inspection types with environmental lighting requirements, such as fluorescent magnetic particle inspection (which needs to be carried out in a dark environment using fluorescence observation), the camera equipment cannot effectively present the inspection results. For this type of inspection, remote witnessing is not effective.
(2) Remote witnessing requires high hardware equipment and network environment requirements. The clarity of videos depends on the pixel indicators and overall performance of the camera equipment, and requires high-quality network coverage. Video storage requires a large capacity hard drive, and hardware configuration is crucial for the smooth progress of witnessing.
(3) Remote witnessing requires camera personnel to continuously follow the inspectors and adjust the camera position. For special locations such as high-altitude operations, sufficient safety facilities need to be configured, otherwise it is not recommended to implement.
4.3 Development space for remote witnessing
With the development of technology, VR devices have been widely used in multiple industries, and people are no longer satisfied with flat 2D effects. Bold assumptions are made regarding the 2D effects of remote witnessing, and the development of remote witnessing will also shift from 2D real-time transmission to 3D, allowing customers to observe the status of casting products manufacturers, and steel castings more in person.
This article introduces an implementation case of a method for remote witnessing of steel castings used by casting products manufacturers. Through the use of video conferencing software on camera equipment, the purpose of remote witnessing and acceptance is achieved under wireless network coverage. The online inspection advantage of this method avoids the waiting and stagnation of inspection caused by travel restrictions for representatives from all parties, and provides a new inspection solution in special environments such as epidemics.