The Main Sensor Types and What Each One Measures
Selecting sensors requires matching physical transduction principles to measurands while accounting for thermal drift, noise floor, and fab availability.
Load Cell Design
Structural Configuration
Physical geometry of a force transducer determines its response to applied loads and its resistance to extraneous moments. Effective load cell design balances the need for high sensitivity in the primary axis with the requirement for mechanical stiffness to ensure the device returns to zero after every measurement. Engineers select materials like stainless steel.
The arrangement of strain gauges on the spring element converts mechanical deformation into an electrical signal.
Stress Distribution
Finite element analysis identifies areas of uniform strain where sensing elements can be most effectively bonded. In a typical load cell design, the Wheatstone bridge circuit compensates for temperature effects and cancels out signals from off-center loading. This configuration ensures that only the vertical force is measured.
Bending beams and shear beams represent common structural approaches for different weight ranges.
Environmental Protection
Sealing methods prevent moisture and contaminants from reaching the internal sensitive components. A durable load cell design incorporates bellows or hermetic laser-welding to maintain performance in washdown environments where high-pressure cleaning is frequent. Entry points for cables are vulnerable.
Selection of the cable jacket material depends on chemical exposure at the installation site.
Overload Protection
Loading beyond the rated capacity is prevented by the integration of mechanical stops.