A disposable calibration device is used to calibrate a measurement system which transmits radiation or acoustic waves to a material or tissue in order to effect measurements. The disposable calibration device includes a structure with a window through which the radiation or acoustic waves can be transmitted, as well as a removable calibration target arranged on the window and capable of returning a portion of the radiation or acoustic waves for calibrating the measurement system. The removable calibration target can be peeled from a window to allow a measurement to be made on the material or tissue. Once a measurement is complete, the disposable calibration device can be discarded and a new calibration device can be inserted on the measuring system.