Common Problems and Solutions for Load Cell Failure

In modern industrial production, especially in the automated production process, the first thing to be solved is to obtain accurate and reliable information, which requires various sensors to monitor and control various parameters in the production process, make the equipment work in a normal state, and make the quality of the product got achieved. Therefore, it can be said that without many excellent sensors or digital load cell, modern production has lost its foundation.

 

With the advancement of technology, electronic weighing instruments made by load cells have been widely used in all walks of life. Different types of load cells have achieved rapid and accurate weighing of materials. Especially with the emergence of microprocessors and the continuous improvement of industrial production process automation, load cells have become a necessary device in process control. Resistance strain type load cells are produced in large quantities by enterprises because of their simple manufacturing process and relatively low processing cost. It has been widely used in industrial production process detection and control, automatic measurement and other fields in various countries.

 

The load cell is actually a device that converts the quality signal into a measurable electrical signal output. Its working principle is to convert the weight of the object added to the weighing pan into an electrical signal proportional to the weight. Then the output electric signal is amplified and A/D converted, and the weighing information is displayed by the relevant circuit. Among them, the resistance strain type load cell has been widely used in weighing instruments because of its simple structure, high accuracy and strong stability.

 

The failure of the resistance strain sensor in use will often cause the weighing system to drift, display unstable or not display data and other phenomena. There are many reasons for sensor failures, but they can be summarized as internal and external reasons. The internal reason is mainly the fault caused by the sensor itself, and the external reason is the damage of some man-made or natural factors.

 

 

1. Temperature changes

All measurement equipment will have a certain degree of error, which is unavoidable. In load cells, drastic temperature changes can cause the metal to warp. Traditional load cells are constructed using strain gauges, which are precision metal parts. Severe temperature changes will affect the function of the strain gauge, which in turn affects the load cell. To solve this load cell problem, you can take temperature readings at different times. If the device causes a drastic temperature change, please protect it from sunlight.

 

 

2. Noise

When the load cell transmits its electrical signal to the weighing controller, interference or noise may destroy it. Proper shielding and grounding of the shielding layer around the load cell cable can prevent noise interference. In a capacitive digital load cell, the signal is converted to a digital signal locally in the load cell, so there is no loss of signal over the entire cable length or at a bad connection point.

 

 

3. Moisture

Moisture also suppresses the signal from the load cell to the weight controller. Steam, excessive humidity, or equipment cleaning causes it to enter the load cell through the cable entry area. The airtight seal will prevent moisture from damaging the load cell and internal components.

 

 

4. Balance the load

The load must be properly balanced on the load cell, or the load cell must be arranged to accommodate unbalanced loads. If multiple load cells are used, they must be installed so that the container or other parts of the container do not bear part of the load. For boats, this usually means that the load cell must be located between the boat and the ground. For the installed load, the bumpers and check valves used to stabilize the load cannot support its weight.