Analysis of sensitivity of cold stages on Philips CM12 to sources of vibration

A simple apparatus has been designed and constructed to measure the position of the high-magnification image of a sharp edge with millisecond time resolution. By Fourier transform analysis of the resulting signal, it is possible to analyse any image blurring that is present into the spectrum of frequencies of which the vibrations or movements causing the blurring are composed. Using this apparatus, the sensitivity of a variety of side-entry cold stages to sources of vibration has been analysed in a Philips CM12 electron microscope. Ambient vibration present in the room environment or the water supply and affecting the image resolution can be identified and, hopefully, removed. The sensitivity of the stage/microscope combination to airborne vibrations can also be rapidly analysed by the use of a white or pink noise source played through a loudspeaker in the room. The apparatus can thus help to understand any hypersensitivity to vibrations and thereby suggest improvements in the stage design. The design could be implemented on any other microscope.