Protection and sealing failure analysis

In today's increasingly fierce market competition, product performance determines the life of an enterprise. In order to solve the currentSubmersible Level TransmitterDue to the problems of low service life and high return rate, we disassembled, tested and analyzed the repaired sensors. Through research, it is found that sensor failure is mostly caused by poor protection and sealing performance of the sensor. The sensor is immersed in water for a long time during operation. If the sealing performance is poor, the sensor can be easily penetrated by moisture. However, the resistance strain gauges and compensation circuitry in the sensor cavity are susceptible to moisture. When the strain gauge and compensation circuit are affected by moisture, the stability of the sensor will decrease, leading to overall failure of the sensor.

The submersible level gauge was dismantled and repaired after surveying for the groundwater level monitoring project. It was found that the following key parts of the input level transmitter are prone to sealing failure, such as the circuit board of the diaphragm assembly itself, the circuit board of the operational amplifier, and several important connection parts of the sensor itself. These partial seals are not ideal. If it is immersed in water for a long time, water and humidity will enter the sensor cavity from between the sensor tail and the cavity, between the diffused silicon core clamp and the diffused silicon core, and between the diffused silicon core and the sensor cavity. Failure of these local seals will destroy the normal working environment of the sensor. Not only that, most circuit boards themselves lack necessary protection measures, exacerbating the damaging effects of moisture. There are various compensation circuits in the sensor cavity. Once water and humidity enter the junction box, it will cause the sensor insulation to decrease or even pass through, causing the sensor zero position to be unstable or damaged. Therefore, it is necessary to improve the housing structure and production process of the sensor to effectively improve the sealing performance of the sensor.