ABB PCD235B1101 3BHE032025R1101

ABB励磁控制器模块 PCD235B1101 3BHE032025R1101

传感器的结构设计针对表压传感器的密封防护和防水性的要求，综合各方面考虑在传感器外壳上端设计了安装防水透气组件的通气孔，以此来实现整个传感器的通气和防水功能。图3 为传感器通气结构示意图。

与防水透气组件对接的螺纹接口处使用密封圈密封，从而保证传感器与外界环境的连通，通过组件可以隔绝水分进入传感器内部，达到透气防水的目的。为了保证防水和防振动的效果，在螺纹处涂抹少量螺纹保护胶。1.4.2 防水透气组件设计

防水透气组件选择金属材料，通过螺纹连接方式安装到传感器的合适位置，同时应考虑工作温度、环境湿度、防水要求和冲击、振动等环境适应性要求。

防水透气组件内部为通孔设计，使得组件与外界环境相通，将聚四氟乙烯膨化材料填充在组件内部，四周压紧，防止水分从聚四氟乙烯膨化材料与组件安装面进入，组件采用螺纹机械接口，可以设计成M3/M4 等直径较小螺纹，为后续组件安装预留足够安装空间，组件如下图所示。2 实验验证

2.1 透气实验表压传感器是通过感受测试介质和大气压力差值输出差分的信号。若传感器透气性不好，使传感器内外存在明显压差，将导致传感器在不同的海拔高度下测试输出有明显差异。

通过低气压试验箱进行透气性试验，在海平面和海拔7 620m 高度下分别进行传感器性能测试，测试结果及对比结果见表1。

结果表明从海平面到海拔7 620m传感器输出信号变化较小。说明在从海平面到高海拔过程中，传感器内部气体的大气压力也随着海拔高度的升高而发生改变，只有当传感器内部气体压力与外界环境气体压力相等时，才能使得传感器的表压输出信号不发生改变。实验证明海拔高度升高过程，传感器内部气体可自由出入传感器，因此可证明材料透气性良好。2.2 防水实验

The structural design of the sensor is aimed at the sealing protection and waterproofing requirements of the gauge pressure sensor. Taking into account various factors, a ventilation hole for installing waterproof and breathable components on the upper end of the sensor shell is designed to achieve the ventilation and waterproofing functions of the entire sensor. Figure 3 is a schematic diagram of the sensor ventilation structure.

The threaded interface connected to the waterproof and breathable component is sealed with a sealing ring to ensure the connection between the sensor and the external environment. The component can isolate moisture from entering the interior of the sensor, achieving the goal of breathability and waterproofing. To ensure the effectiveness of waterproofing and vibration prevention, apply a small amount of thread protection adhesive to the threads. 1.4.2 Waterproof and breathable component design

The waterproof and breathable components should be made of metal materials and installed in the appropriate position of the sensor through threaded connections. At the same time, the working temperature, environmental humidity, waterproof requirements, and environmental adaptability requirements such as impact and vibration should be considered.

The interior of the waterproof and breathable component is designed with through-holes, allowing the component to communicate with the external environment. PTFE expanded material is filled inside the component, and the surrounding area is tightly pressed to prevent water from entering from the PTFE expanded material and the installation surface of the component. The component adopts a threaded mechanical interface, which can be designed into smaller diameter threads such as M3/M4, leaving sufficient installation space for subsequent component installation. The component is shown in the following figure. 2 Experimental verification

2.1 Ventilation experiment

The gauge pressure sensor outputs a differential signal by sensing the difference between the test medium and atmospheric pressure. If the permeability of the sensor is poor, there will be a significant pressure difference between the inside and outside of the sensor, which will result in significant differences in the test output of the sensor at different altitudes.

The permeability test was conducted using a low pressure test chamber, and the sensor performance was tested at sea level and altitude of 7620m. The test results and comparison results are shown in Table 1. The results indicate that the output signal of the sensor varies slightly from sea level to altitude of 7620m. During the process from sea level to high altitude, the atmospheric pressure of the gas inside the sensor also changes with the increase of altitude. Only when the internal gas pressure of the sensor is equal to the external environmental gas pressure can the gauge pressure output signal of the sensor remain unchanged. Experiments have shown that during the process of elevation increase, the gas inside the sensor can freely enter and exit the sensor, thus proving that the material has good breathability. 2.2 Waterproof experiment