EMS 850 Critical Point Dryer and Accessories
Product Details
Description
Critical Point Drying (CPD)
Along the boundary between the liquid and vapor phases, there is an area at the appropriate temperature and pressure, where liquid and vapor can coexist and have approximately the same density. Critical point drying uses this physical principle to avoid the transition from the liquid to the gas phase. The material is brought to slightly above the critical temperature and pressure and then back to environmental pressure. This avoids damage to the fine structure and enables e.g. high-resolution microscopic imaging or the production of finely structured materials.
Pressure-temperature phase diagram verdampfung.png: Saperaud derivative work: Master Uegly, Phasendiagramm Verdampfungen, CC BY-SA 4.0
The EMS 850
The specimens for critical point drying are located in the pressure chamber. The chamber is pre-cooled to allow it to be readily filled with liquid CO2 from a gas cylinder. The chamber is then heated to just above the critical temperature with subsequent critical pressure being achieved. The CO2 gas is vented through a needle valve, to avoid specimen distortion.
The EMS 850 is fitted with precise heating and cooling elements for a controlled temp. range of +5°C to 35°C. This ensures the accurate achievement of the critical point without exceeding pressures, temperatures and with no need to rely on pressure relief valves to control pressure during the heating cycle.
The chamber is vertical, with top loading, to ensure specimens do not become uncovered during the drying process. A side viewing port enables the location of the meniscus for the correct level when initially filling the chamber.
The standard specimen holder has 12 individual chambers (8 mm diameter x 8 mm high) and allows easy exchange and transfer to and from the EMS 850. For delicate specimens porous pots are available.
The EMS 850 is fitted with three valves: fluid inlet, flushing and a gas venting system, which uses a fine needle valve to give controlled pressure let down at the end of the critical point drying process. Therefore a flow gauge is no longer required.
A separate flow meter is available, if your application requires highly accurate monitoring and/or flow control.
Key Features
- Vertical chamber with top filling and bottom draining
- Built-in adiabatic cooling and thermoelectric heating
- Fine-control needle valve pressure let down
- Built-in magnetic stirrer for solvent exchange
- Illuminated chamber with side viewing port
- Pressure monitoring with pressure relief valve and rupture disc protection
- Three-year Warranty
Specifications
Specimen Chamber | 32mm (Diameter) x 47mm (Height), Tested to 3000 psi |
Temperature Gauge | 0-120°C |
Thermal Cut-Out | 40°C |
Pressure Gauge | 0-3000 psi |
Pressure Relief | At 1500 psi |
Rupture Disc | At 1900 psi |
Cooling/Heating | +5°C to +35°C |
Two On/Off Valves | Inlet/Outlet/Cool/Vent Needle Valve Letdown |
Supply | 115V 60Hz (6A max) / 230V 50Hz (3A max) |
Instrument Case | 450mm (W) x 350mm (D) x 175mm (H) |
Weight | 12Kg |
Operation | Requires CO2 gas cylinder direct connection by high pressure hose (High pressure hose included with instrument) |
The EMS 850 includes
- Base unit
- Vertical chamber with glass viewing port and safety shield
- Magnetic stirrer located under the base of the chamber
- Controllable adiabatic cooling and heating with digital read out
- CO2 inlet valve, flushing valve and venting system and high pressure CO2 coupling hose
- Standard 12 specimen holder
- Operating manual