Analysis of the reasons for the high failure rate of weighing sensors

Load cell accuracy is directly related to measurement accuracy and production safety. However, in practical applications, the persistently high failure rate of load cells troubles many enterprises, not only increasing maintenance costs but potentially leading to production interruptions, data deviation, and other serious consequences. In-depth fault analysis reveals that the failure rate is closely related to the correctness of the initial matching, and the specific operating conditions and standards of different application scenarios also significantly impact the sensor's lifespan. This article, based on case studies and practical application scenarios, systematically analyzes the key reasons for the high failure rate of load cells, starting from the initial selection stage.

I. Improper Initial Matching: The Sensor's "Congenital Flaw"

Initial matching is the fundamental step in load cell application. If there are selection biases or unreasonable parameter configurations at this stage, it will directly implant a "congenital flaw" in the sensor, significantly increasing the probability of failure during subsequent use.

Rated Capacity is the core parameter for load cell selection. Whether the capacity is chosen too small or too large, it will negatively affect the sensor's operational stability.

• When the rated capacity is chosen too small: The sensor is prone to overload issues in practical use.

  • Case Example (Auto Parts Manufacturer): To save costs in the weighing step of a production line, the company chose a 500kg rated capacity load cell. However, the single weight of the parts being weighed often reached 450-480kg, and there were internal impact loads during material transfer. After only 3 months of use, the sensor frequently exhibited faults such as signal drift and extremely poor linearity. Inspection revealed that the internal elastic body of the sensor had permanent plastic deformation due to overload, and could not return to normal function.

• Conversely, when the rated capacity is chosen too large: The sensor will operate long-term in a low-load state, which leads to a reduction in sensitivity and an inability to capture subtle weight changes, thereby introducing data errors.

  • Case Example (Food Processing Plant): A batch of 200kg rated capacity sensors was used for flour packaging equipment where the maximum weighing requirement was only 50kg. During the production process, technicians found frequent data fluctuations, with batch differences in flour package weights reaching 500g, far exceeding the industry standard error range. Technical investigation revealed that because the sensor's rated capacity was significantly greater than the actual load, the resolution of the output signal was insufficient to accurately measure the small changes in the weight of the dispensed material, ultimately leading to failure.