What is a load cell?
The Wheatstone bridge circuit (now used to measure strain on the surface of a supporting structure) was improved and popularized by Sir Charles Wheatstone in 1843 is well known, but thin films vacuum deposited in this old tried and tested circuit The application is not well understood yet. Thin film sputter deposition processes are nothing new to the industry. This technique is used in many applications, from making complex microprocessors to making precision resistors for strain gages. For strain gages, thin-film strain gages sputtered directly onto a stressed substrate are an option that eliminates many of the problems faced with “bonded strain gages” (also known as foil gages, stationary strain gages, and silicon strain gages) .
What does the overload protection of the load cell mean?
Each load cell is designed to deflect under load in a controlled manner. Engineers optimize this deflection to maximize the sensor’s sensitivity while ensuring the structure operates within its “elastic” region. Once the load is removed, the metal structure, deflected with its elastic region, returns to its initial state. Structures that exceed this elastic region are called “overloaded”. An overloaded sensor undergoes “plastic deformation,” in which the structure permanently deforms, never returning to its initial state. Once plastically deformed, the sensor no longer provides a linear output proportional to the applied load. In most cases, it is permanent and irreversible damage. “Overload Protection” is a design feature that mechanically limits the sensor’s total deflection below its critical load limit, thereby protecting the sensor from unexpected high static or dynamic loads that would otherwise cause plastic deformation .
How to determine the accuracy of the load cell?
The accuracy of the sensor is measured using different operating parameters. For example, if a sensor is loaded to its maximum load, and then the load is removed, the sensor’s ability to return to the same zero-load output in both cases is a measure of “hysteresis”. Other parameters include Nonlinearity, Repeatability, and Creep. Each of these parameters is unique and has its own percentage error. We list all these parameters in the datasheet. For a more detailed technical explanation of these accuracy terms, please see our glossary.
Do you have other output options for your load cells and pressure sensors besides mV?
Yes, off-the-shelf signal conditioning boards are available with power up to 24 VDC and three types of output options are available: 4 to 20 mA, 0.5 to 4.5 VDC or I2C digital. We always provide soldered-on boards and are fully calibrated to max load sensor. Custom solutions can be developed for any other output protocol.
Post time: May-19-2023
