Aspects of the present disclosure are directed to force sensors. As may be implemented in accordance with one or more embodiments, an apparatus includes a force-responsive component having a resonant frequency, and a circuit that compensates for variations with the force-responsive component. The force-responsive component moves in response to an applied force, in accordance with a spring constant that is susceptible to fluctuation. The compensation circuit determines Brownian motion of the force-responsive component at the resonant frequency based on temperature, and generates an output based on the determined Brownian motion and movement of the force-responsive component. Such an output is indicative of force applied to the apparatus.