A device includes a guard member, at least one bias sensor, a display, and a measurement sensor. The guard member includes an aperture on an axis. The at least one bias sensor is coupled to the guard member. The at least one bias sensor is configured to provide a bias signal corresponding to a bias force on the guard member. The bias force is aligned parallel with the axis. The display is coupled to the at least one bias sensor and is configured to provide a visible indication of the bias force. The measurement sensor is configured to provide an output signal corresponding to a measured force proximate the aperture.