The selection of load cell includes material, structure, range, etc., which is described in detail in a professional paper. I'm just going to talk a little bit about how do you choose the load range?

The range is also called the rated load of the sensor. In general, when the center is fixed or the load is evenly distributed, choose according to this formula: the rated load of the measuring system =(the sum of the rated load of several sensors *30% ~ the sum of the rated load of several sensors *70%).

• The rated load of the measuring system: includes the total weight of the measuring material, the carrier (weighing table), the support, etc.
• The static load stability, overload and shock risk of the measurement system are generally selected between 50% and 70%.
• The measurement system dynamic load fluctuation, overload and shock risk is higher, generally choose between 30% and 50%

To determine if a load cell is quarter-bridge, half-bridge, or full-bridge, you need to examine the wiring configuration of the load cell. Here are the steps to determine the type of load cell:

Identify the number of strain gauges: Load cells typically contain strain gauges that measure the deformation of the load cell when subjected to a force. Count the number of strain gauges present on the load cell.

Determine the wiring configuration: Load cells can be wired in different configurations, which determine their type.

• Quarter-Bridge: A quarter-bridge load cell has only one strain gauge. It is wired in a quarter-bridge configuration, where one end of the strain gauge is connected to the load cell and the other end is left open. The strain gauge forms a quarter of a Wheatstone bridge circuit.

• Half-Bridge: A half-bridge load cell has two strain gauges. It is wired in a half-bridge configuration, where the two strain gauges are connected in parallel and one end of the parallel combination is connected to the load cell. The other end is left open. The strain gauges form half of a Wheatstone bridge circuit.

• l Full-Bridge: A full-bridge load cell has four strain gauges. It is wired in a full-bridge configuration, where all four strain gauges are connected in a Wheatstone bridge circuit. The bridge circuit provides better accuracy and compensation for temperature changes.

By following these steps, you can determine if a load cell is quarter-bridge, half-bridge, or full-bridge based on its strain gauge configuration and wiring.

A load cell is a type of transducer that is used to convert a mechanical force or load into an electrical signal. It is commonly used in various industries and applications to measure and monitor the weight or force applied to it.

The primary function of a load cell is to accurately measure the force or load applied to it and convert it into an electrical signal that can be further processed and analyzed.

Load cells typically consist of a strain gauge or multiple strain gauges that are bonded to a metal structure. When a force or load is applied to the load cell, it causes deformation in the metal structure, which in turn changes the resistance of the strain gauge(s). This change in resistance is then converted into an electrical signal proportional to the applied force or load.

Load cells are used in a wide range of applications, including weighing scales, industrial automation, material testing, force measurement, and process control. They provide accurate and reliable measurements of weight or force, and their output can be easily integrated into various control systems or data acquisition systems for further analysis or automation.

• Measurement: An analogue load cell measures the force or weight applied to it and converts it into an electrical signal proportional to the load. This signal is typically an analog voltage or current. On the other hand, a digital load cell directly measures the load and converts it into a digital signal, usually in the form of binary code.

• Accuracy: Digital load cells generally offer higher accuracy compared to analogue load cells. The digital signal is less susceptible to noise and interference, resulting in more precise and reliable measurements.

• Signal Transmission: Analogue load cells transmit the electrical signal through analog wires, which can be susceptible to noise and signal degradation over long distances. Digital load cells, however, transmit the digital signal digitally, typically through a serial communication protocol such as RS-485 or CAN bus. This digital transmission ensures better signal integrity and allows for longer cable lengths without significant loss of accuracy.

A miniature load cell is a small-sized device used for measuring and monitoring force or weight. It is designed to be compact and lightweight while still providing accurate and reliable measurements.

Miniature load cells are commonly used in applications where space is limited, such as in robotics, aerospace, medical devices, and industrial automation.

These load cells can be used to measure compression or tension forces and are often integrated into systems for force testing, quality control, or feedback control purposes.

Precision and accuracy can be said to be the comprehensive measurement error of the load cell. The technical indicators of the sensor itself are divided into linearity, hysteresis, creep, repeatability, temperature performance and so on. The accuracy rating is generally a comprehensive description of its performance. Weighing and force measurement are different, marking methods are different. For example, in the weighing apparatus: C3(the error of different range segments is different, it is based on a horn error envelope); It is necessary to emphasize the high precision of small letters and large numbers, and the accuracy of C3 is greater than that of D1. Force measurement: 0.02(as a percentage of rated load). The smaller the value, the higher the accuracy, and the accuracy of 0.02 is greater than 0.05.

Sensitivity refers to the value of the sensor output under the rated load, the unit is mV/V, for example, it is determined that no load is 0mV/V, and the output of 2mV/V under the rated load is 2mV when the excitation voltage is 1V. Then when the excitation voltage is X, load to the rated load sensor output 2*XV(the actual excitation voltage of the sensor is mostly chosen to be 5-15V). Do not think that sensitivity is the sensitivity of the sensor response.

The load rating refers to the maximum weight of the sensor. Safe load means that the sensor is safe when used in this load, although plastic deformation will not occur and lead to the failure or failure of the sensor, but the measurement performance and related parameters are seriously out of tolerance will lead to the measurement system can not work normally.

The limit load means that the sensor will not break and cause safety accidents within this load range. Therefore, it is recommended to ensure that the sensor does not exceed the rated load.

Combined with the fatigue failure of strain gauges and elastic components, it is generally believed that the service life of the sensor is 10-10 times close to the rated load. The overload, side load, high frequency impact and so on are caused by selection and protective factors in actual use. And it is easy to lead to sensor failure, or even scrap.

The shelf life of the load cell is not clearly defined, and it is not easy to give a shelf life of 10 years or 20 years. From the practical application point of view, whether it is industrial field or laboratory, there are many cases of normal use for more than 10 years without any fault. However, it must be clear that the performance of the sensor placed for a period of time, or even a few years, is more stable, because the residual stress of the sensor is completely released after placement.

To replace the sensor, it is necessary to ensure that the rated load, sensitivity and output impedance in the technical parameters are the same. That is to say, no matter what structure and brand of sensor you use, as long as you can install it to ensure that the force value can be accurately transmitted, it can be completely replaced.

In actual operation, it is still recommended that non-professionals do not change the sensor structure, and seek a consistent installation size to replace it. At the same time, pay attention to the accuracy level marked on the sensor, and the high accuracy level can replace the low level. It needs to be emphasized here that only need to check the installation size when looking for alternative sizes, there is no need to pay attention to all dimensions, most manufacturers install the same size but the total length has a few mm deviation or slightly different shape.

The above is analog weight sensors, as for digital weight sensors, because each communication protocol is different, and the same manufacturer may also be encrypted sensors and instruments, so this type of sensor replacement is best to find the previous supplier. The purpose is to protect their own customer resources so that others can not change.

Load cell weighing sensor is a core component in the entire measurement system, for any component can not achieve 100% pass rate, even if the manufacturer in the factory before the test, but it is inevitable that there is a very low probability of potential failure due to process defects and aging.

Most of the faults of the sensor can not be detected without professional instrumentation and test equipment. An ordinary digital multimeter can only measure the input and output impedance of the sensor bridge. Nothing else can be measured.

The insulation resistance of the sensor is generally at least ≥2000MΩ, and it is also necessary to measure the insulation resistance tester or megohm meter. When the bridge voltage is 10V(and the voltage must be provided by the regulated power supply), the zero point and signal output value of the sensor are measured by at least 4 and a half bit or more, and a stable standard force source is also required for loading. Ordinary multimeters are simply used to measure whether the bridge is burned or broken due to lightning strikes, surge voltages, etc.