Standard SEM Coolstage -25°C to +50°C
With increased use of Low Vacuum or Variable Pressure microscopes, many microscopists now appreciate the need to control water sublimation from wet samples. By cooling a wet specimen, water sublimation may be slowed or depending on chamber pressure stopped altogether. Saturated vapour pressure of water decreases considerably with temperature.
At room temperature water will very quickly sublimate causing considerable changes to the specimen structure. At 300Pa, specimen temperature needs to be less than -9.5°C and at 85Pa specimen temperature needs to be less than -25°C to stop sublimation. Therefore by cooling a specimen to -25°C, chamber pressure may be 85Pa with limited sublimation from the specimen. Advantages of this procedure are clear to see, by cooling a specimen in low vacuum, changes in specimen structure due to sublimation can be minimised and the ability to operate at higher vacuum provides a better signal to noise ratio and clearer images. With ESEM SEMs where imaging is possible in a gaseous environment temperature and vacuum can be perfectly matched to keep the specimen fully hydrated during imaging.
The Deben Coolstage can also be used for high vacuum heating and cooling applications inside the SEM.
The Deben Coolstage is available for all SEMs and guaranteed temperature range is +50°C to -25°C (at 300Pa chamber pressure) or less than -30°C at higher vacuums.