Force balanced transducer based on electromagnetic lever with improved linearity

• The principle of the electromagnetic force transducer.
• Simulating the nonlinear relationship between electromagnetic force and voltage.
• Analysis of the nonlinearity of the electromagnetic force.
• Obtaining the linear electromagnetic force by nonlinear compensation.
• Demonstrating result by experiment.

The elastically sensitive element nonlinearity and the signal–noise ratio are the limitation of the traditional force transducer, which makes the precision is rarely higher than 0.02%. This study proposes a force transducer with electromagnetic force balance lever structure. The transducer utilized a controllable electromagnet that generated the controllable electromagnetic force to offset the load while the load value is obtained by the coil voltage, which solves the signal–noise ratio problem. Analyzing the electromagnetic force curves under different temperatures by the piecewise linearization method acquires the high linearity electromagnetic force, which solves the nonlinearity problem. Test results indicated that the transducer linearity was 0.001%, and its precision was 0.003%.