A method of calibrating a biometric device useful to measure a target dim ension of a physiological tissue is provided comprising the steps of: measur ing the target dimension of at least two samples of a reference material wit h the device to provide an actual output, wherein the reference material pos sesses at least one property of the tissue required for the function of the device and wherein each of the samples has a known target dimension; calcula ting a calibration equation based on the actual output of the device and the known target dimensions of the samples; and adjusting the actual output of the device according to the calibration equation to yield a corrected output . The calibration method provides a means of obtaining accurate tissue measu rements. Also provided is a method of using a biometric device to measure a target dimension of a physiological tissue which incorporates calibration.</ SDOAB>
