For radiological maintenance technicians, this topic seems very simple, but in the actual work, the preliminary preparation work has a pivotal role. If the X-ray machine before the installation can not be skilled, as soon as possible, standardized to develop the installation workflow, the lack of a comprehensive, systematic design concept, it will be for future installation work, the actual operation of a lot of inconvenience, now combined with their actual work, the installation of the X-ray machine preliminary preparation work summed up several lessons and colleagues.
1) Grounding problem
Grounding is a very important work for the installation and use of X-ray machines. It has two meanings, on the one hand, it is safe grounding, which is for the personal safety of staff and patients. On the other hand, working grounding is to find a drain point or a circuit measurement reference point for each circuit. The success and failure of grounding work is one of the key issues related to the safety of personnel life and the normal use of machines. Grounding is measured by the grounding resistance value and must be inspected regularly by functional departments. The value is within the specified range and cannot break the upper limit value. General common X-ray machine ground point resistance ≤3 ohms, special purpose machines such as: vascular subtraction,(DSA) requirements ≤1 ohms. The production method is: if the conventional method is dug from the ground (1.5~2) meters deep, the pit area is (1~1.5) square meters, the cost of laying a certain thickness of copper plate at the bottom of the pit will be very high, and the contact of the lead wire is only one, which is unstable. In practice, three galvanized pipes (50 mm in diameter and 2500 mm in length) can be used, each galvanized pipe is 3 meters apart, and thrown into the ground. The galvanized pipe head is 300~500 mm away from the ground. Each pipe is connected with a flat iron, and the ground wire is welded with each galvanized pipe to lead to the terminal post of the ground wire. The machine outlet ground wire is also connected to the terminal. This method can meet the requirements of the machine, low cost, easy operation, and high stability, should be the preferred method in the work.
2) Power supply problem
According to the different requirements of the machine for the internal resistance of the power supply, the main consideration is the size of the instantaneous power of the machine the length of the distance from the power transformer, and the size of the wire diameter (copper core wire) of the power line of the machine. Generally, the power line (copper core) of the ordinary X-ray machine and gastrointestinal X-ray machine is 30 square millimeters, and the power line diameter of the more special machines such as : DSA, CT, and other power lines is 50 square millimeters. Power line according to the three-phase five-wire system (three-phase lines, one neutral line, one ground line) or three-phase four-wire system (three-phase lines, one neutral line, the ground line is connected), pay attention to the phase sequence of the phase line. The power control box is arranged in a convenient position for opening and closing in the control room.
3) Room design
Including machine room and control room design. According to the requirements of machine type, performance, convenience of work, and radiation protection. Comprehensive consideration and reasonable design are also important preparatory work. Because the X-ray machine is special, the X-rays produced have certain radiation damage to the human body, so the protection of the staff is a very important work, which must be paid great attention to. Under the condition of ensuring that the protection of the staff and the working environment meets the national standards, the rationality of the room layout and the convenience of the work are considered. According to the performance of the machine, first, determine the location of the machine's center point in the room. In addition, the room height refers to the actual height of the room ceiling from the ground (net height after decoration), to meet the requirements of the maximum distance of the machine operation, so as not to affect the operation. The design of the observation window (commonly known as lead glass) requires lead glass with a certain lead equivalent radiation protection, located in the horizontal center of the wall, and the actual distance between the lower height and the ground (800~850) mm. The wall hole between the machine room and the control room is preconfigured for the cable connecting the console the control cabinet and the bed. Generally, the frequency of the machine is power frequency, medium and high frequency, and the preparation of the power regulator. The size of the wall hole is generally square or round, the size is 200mm × 200mm, 100 mm from the ground, and the number is 1 to 2. If a new machine room is built, the underground cable trench should be reserved, and the size of the cable bridge should be determined by the machine model and the number of cables (to be used overhead). The design of the room door consists of the equipment room door and the control room door. This door needs special treatment, emphasizing the protection performance and convenient opening. It is recommended to use two doors in the shape of the equipment room door.
4) Installation summary
In short, the installation of the machine is a comprehensive project that requires coordination with various departments of the hospital. As a radiological maintenance engineer, it is necessary to master the overall situation, not anxious or dry, and gradually implement it according to steps and plans to create favorable conditions for the smooth installation of the machine.