Automatic critical-point dryer

K850/K850WM from Quorum Technologies

Critical point dryer K850 combines versatility and ease of operation. Built-in thermo-electric heating and adiabatic cooling allow precise temperature control. The vertical pressure chamber (32 mm in diameter x 47 mm in height) has a side viewing port which allows a clear view of the liquid meniscus.
K850WM is a compact device for drying a complete 6” wafer.  A convenient wafer holder allows quick transfer and avoids pre-drying.

  • Automatic thermoelectric heating
  • Adiabatic cooling
  • Digital temperature monitor
  • K850WM option for 6"/150 mm wafers

Further information

Critical point dryers are used for drying biological samples prior to examination in a scanning electron microscope. Further areas of application are the dehydration of samples in pharmacology, histology and pathology. Critical point dryers are also more and more used in the semiconductor industry to avoid the tearing of extremely fine structures during the drying process. As a precondition, water has to be removed from the sample by replacing it with an increasing alcohol concentration. After the alcohol has been completely expelled by liquid CO2 during the drying process, the temperature in the pressure chamber can be increased. As a result, the chamber pressure also increases. When the critical point is reached, the carbon dioxide phases dissolve. After draining the CO2, the sample is dry  without being exposed to a phase boundary (liquid/gaseous).


Specifications K850
Dimensions and weight 450 mm w x 350 mm d x 175 mm h, 12 kg
Recipient 30 mm Ø x 40 mm h, vertically mounted with CO2-inlet at top and drain of solvent at bottom
Temperature-/pressure monitoring Fitted with thermo-electric heating and adiabatic cooling enabling temperature control of +5 °C cooling and +35 °C during heating, thermometer (0 – 120 °C) und manometer (0 – 2.000 p.s.i./ca. 137 bar), normal working temperature and -pressure 35 °C @ 1.350 p.s.i. (approx. 93 bar)
Controls Fitted with three valves: fluid inlet, flushing and a gas venting system which uses a fine needle valve to give controlled pressure let down
Magnetic stirrer for enhanced solvent exchange
Side viewing port gives a good view of the liquid meniscus during filling
Safety cut out for over pressure (ca. 1.700 p.s.i./ca. 117 bar),
pressure tested up to 3.000 p.s.i./approx. 206 bar
Supplied with 1 x stainless steel specimen holder (12 compartments: 8 mm Ø x 8 mm), 10 x PTFE porous specimen pots (12.7 mm x 15.7 mm, pack 10), high pressure CO2 hose, operating manual & test certificate
EK4135 Microscope cover-slip holder Ø 13 mm
EK4140 TEM grid holder, 8 grids
EK4130 Holder for bulk samples, ca. 25 x 30 mm
CPD800A Pots specimen 12.5 mm, porous size 78 μm, 10 pack
For operation a CO2 bottle without pressure reducer but with riser pipe is necessary.


Critical-point dryer brochure
Large chamber critical-point dryer K850WM
Critical-point dryer specification


Anne Kast
Anne Kast

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Quantum Design GmbH

Im Tiefen See 58
64293 Darmstadt

Phone:+49 6151 8806-0
Fax:+49 6151 8806920
Anne KastProduct Manager - Electron microscopy
+49 6151 8806-456