A measurement system for examining a sample, the measurement system comprising: an internally reflective element having a contact surface configured to support the sample; a contact member positioned adjacent to the internally reflective element, wherein at least one of the contact member and the internally reflective element are configured to apply a force to the sample when the sample is positioned on the contact surface and the contact member is in contact with the sample; an actuator configured to adjust the force applied to the sample by the contact member and the internally reflective element; an optical assembly comprising a light source and a light detector, wherein the optical assembly is configured to scan the sample by directing source light from the light source towards the contact surface and detecting source light optically interacting with the contact surface by the light detector; a sensor configured to detect a force applied to the sample by at least one of the contact member and the internally reflective element; wherein prior to the scan, an initial force as detected by the sensor is applied to the sample by the at least one of the contact member and the internally reflective element; characterised in that the system is configured such that after the scan, a resulting force applied to the sample by the at least one of the contact member and the internally reflective element is detected by the sensor; and the system further comprises a controller configured to receive a signal from the sensor indicative of the detected resulting force, wherein the controller is further configured to: compare the initial force to the resulting force; determine the initial force and the resulting force are different; and control the actuator to adjust the force applied to the sample by the at least one of the contact member and the internally reflective element from the resulting force to the initial force based on the determination that the initial force and the resulting force are different; wherein the system is configured such that after the force applied to the sample is adjusted to the initial force, the sample is re-scanned by the optical assembly. an internally reflective element having a contact surface configured to support the sample; a contact member positioned adjacent to the internally reflective element, wherein at least one of the contact member and the internally reflective element are configured to apply a force to the sample when the sample is positioned on the contact surface and the contact member is in contact with the sample; an actuator configured to adjust the force applied to the sample by the contact member and the internally reflective element; an optical assembly comprising a light source and a light detector, wherein the optical assembly is configured to scan the sample by directing source light from the light source towards the contact surface and detecting source light optically interacting with the contact surface by the light detector; a sensor configured to detect a force applied to the sample by at least one of the contact member and the internally reflective element; wherein prior to the scan, an initial force as detected by the sensor is applied to the sample by the at least one of the contact member and the internally reflective element; compare the initial force to the resulting force; determine the initial force and the resulting force are different; and control the actuator to adjust the force applied to the sample by the at least one of the contact member and the internally reflective element from the resulting force to the initial force based on the determination that the initial force and the resulting force are different; wherein the system is configured such that after the force applied to the sample is adjusted to the initial force, the sample is re-scanned by the optical assembly.