Definition
A spoke push-pull force gauge is a mechanical sensor used to measure the value of thrust or pull force. Its core structure is composed of spoke-like elastomers and strain gauges, which can convert mechanical force signals into measurable electrical signals, which are widely used in industrial production lines, product quality control, material testing, scientific research experiments and other fields to achieve accurate, dynamic or static measurement of force values.
How it works:
The spoke push-pull force gauge works on the principle of strain electrical measurement. When an external force acts on the bearing end of the sensor, its spoke-like elastomer undergoes a slight deformation. The resistance value of the strain gauge attached to a specific position of the elastomer changes accordingly, thus disrupting the balance of the Wheatstone bridge composed of strain gauges, resulting in a weak voltage signal that is proportional to the external force. This signal is subsequently amplified and processed to convert into an intuitive force reading. Its output relationship can be expressed as:
Uout = K · F · Uin
Among them, Uoutis the output voltage, K is the sensor sensitivity coefficient, F is the applied force value, Uinis the excitation voltage.
Measurement method
The measurement process is usually divided into two modes: static and dynamic. When measuring statically, the force value needs to be applied smoothly and kept stable, and the value in the steady state should be read. Dynamic measurement is used to monitor the process of force value change over time, which needs to be combined with a high-speed data acquisition system. The general steps include: correctly installing the sensor between the force application mechanism and the object to be measured; ensure that the axis of the force coincides with the central axis of the sensor to avoid lateral force; According to the sensor range and the force to be measured, select the appropriate instrument for zeroing and calibration; The load is then applied and the data is recorded. After the measurement is completed, the load should be unloaded and the instrument should be checked for zeroing.
Influencing factors
Measurement accuracy is influenced by various factors. Changes in ambient temperature can lead to changes in elastomer material properties and strain gage sensitivity, usually with a temperature compensation range given by the sensor. Poor concentricity or lateral force and torque of mechanical installation will introduce measurement errors. The stability of the excitation voltage directly affects the accuracy of the output signal. The creep and hysteresis characteristics of the sensor, i.e., the difference in the output over time under constant load or during the load-unload cycle, are also factors to consider. In addition, the length of the signal transmission line, shielding effect, and external electromagnetic interference can affect the signal quality.
Applications:
Because of its compact structure and good anti-bias load, the wheel-spoke push-pull force gauge is suitable for a variety of industrial and scientific research scenarios. In electronics manufacturing, it is used to test the tactile strength of buttons and switches. In the auto parts industry, it is used to detect the assembly force of door and window seals and joysticks. In the packaging industry, it is used to evaluate the peel strength of encapsulated materials. In building materials testing, it can be used to evaluate the connection performance of components. In the field of scientific research, it is a key component of material mechanical property testing, friction coefficient measurement and other experiments.
Key points of selection
Multiple technical parameters should be considered in the selection. The range should cover the maximum value of the measured force with a certain margin, and usually choose a model that puts the commonly used measurement value within the range of 20% to 80% of the range. The accuracy level needs to be determined according to the actual measurement tolerance, and the errors such as nonlinearity, hysteresis, and repeatability are comprehensively considered. The sensor form factor and mounting interface need to match the actual installation space and mechanical structure. The output signal type, such as analog voltage, current, or digital signals, needs to be compatible with existing data acquisition systems. It is also necessary to check the temperature, humidity and possible corrosive media of the working environment to select the housing with the corresponding protection level. For dynamic measurement, it is necessary to pay attention to whether the natural frequency of the sensor is much higher than the frequency of the change of force being measured.