An apparatus capable of determining the force applied to the tip of an electrical impedance spectroscopy probe comprises: an elongate probe comprising a probe tip attached to a handle, the probe tip having a substantially planar distal end for contacting human or animal tissue; a load cell located in said handle and capable of measuring a force Fload cell applied axially along a longitudinal axiswhen said probe tip is in contact with said human or animal tissue; an accelerometer located in the handle for measuring a gravity vector Aaxial; processing means for compensating for the mass of theprobe tip using said measured force and gravity vector to produce a calibrated measurement of force F applied to said probe tip.