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    E3100 Critical Point Dryer

    The E3100 large chamber critical point dryer has been an industry standard for over 35 years and is used in numerous scanning electron microscopy (SEM) laboratories around the world. Primarily used for critical drying of biological and geological specimens, the E3100 can also used for the controlled drying MEMs,  aerogels and hydrogels.

    Key features

    • Proven reliability – over 6,000 critical point dryer installations world-wide
    • Simple robust construction – easy to maintain – many critical point dryer users carry out their own routine maintenance
    • Horizontal chamber and large viewing window – excellent visibility of the fluid level and drying process
    • Safety – the design has been independently type tested to proof pressures in excess of the working pressure and bursting disc rupture pressure
    • Specimen handling – optional specimen holders for coverslips and TEM grids. Porous pots are available for fragile or very small specimens
    • Extended warranty option

    Click here for the product brochure download

    • Product Description
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    • Additional Information
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    E3100 Critical Point Dryer

    The E3100 large chamber critical point dryer has been an industry standard for over 35 years and is used in numerous scanning electron microscopy (SEM) laboratories around the world. Primarily used for the critical point drying biological and geological specimens, the E3100 can also used for the controlled drying of MEMs, aerogels and hydrogels.

    The design of the E3100 features a large, horizontal pressure chamber measuring 63.5 mm internal diameter x 82 mm in length. The chamber has an external water jacket for temperature control and specimens are introduced via a removable rear door. The front of the chamber is fitted with a 25 mm diameter window which gives an unsurpassed view of the liquid level during the critical point drying process.

    Temperature control

    Dial gauges display pressure in the chamber and the temperature of water circulating through the jacket. Three pressure valves permit easy connection to the liquid CO2 cylinder and allow liquid agitation and venting of the chamber.

    A source of hot running water is essential. Cooling is also useful, especially for sequential critical point drying process runs and/or in laboratories where the room temperature may be high.

    The temperature of the E3100 chamber is raised with a hot water supply. Mains water can be used but a more elegant method involves the use of the optional E4860 Recirculating Heater/Chiller which can be used to pre-cool the chamber to below ambient temperature prior to loading specimens and then to heat the chamber to the critical temperature.


    Operator safety is of course an important consideration with all pressure vessels. If during the critical point drying process the pressure and temperature are inadvertently exceeded, a safety bursting disc is incorporated in the chamber support. The design has been independently type-tested to proof pressures in excess of the working pressure and bursting disc rupture pressure.

    Specimen holder (boat)

    An important feature is the design of the E3100 transfer boat. This permits specimens in the intermediate fluid to be transferred to the chamber of the critical point dryer. On sealing the chamber, the intermediate fluid begins to drain and can be replaced with liquid CO2. In this way the specimens are never allowed to dry out during the loading and transfer stage of the critical point drying process.

    The E3100 is supplied with the E3100-01 tissue boat which has three slots each with three tissue baskets, making a total of nine. Optional holders are available and are listed under Ordering Information.

    This product is for Research Use Only. 

    No. E3100AE

    E3100 Large Chamber Critical Point Dryer

    Chamber dimensions: 63.5 mm Ø x 82 mm length.

    Supplied with:

    E3100-01 specimen holder for tissue (boat), 1 m liquid CO2 delivery tube, O-ring and L-gasket set (including window and door bonded seals), spare bursting disc and retaining copper washer, steel bar for tightening/untightening the door, flat wrench (for removing the window retaining ring) and a comprehensive operating manual.

    Options and Accessories

    Specimen holders

    E3100-02. Holder (boat) for microscope coverslips.

    A specially adapted tissue “boat” allow glass coverslips to be held firmly during critical point drying and has a carrying capacity of 21 coverslips.

    E3100-1. TEM grid holder. For 3.05 mm TEM grids (up to three).

    CPD800A. Solvent-resistant porous pots (12.7 mm x 15.5 mm) with lids. Useful for critical point drying very small or very delicate specimens.


    E3100-061. Service kit for E3100 Critical Point Dyer (for use with ethyl alcohol).

    E3100-061/EPDM. Service kit for E3100 Critical Point Dryer (for use with acetone).

    Temperature control

    Hot and cold mains/tap water can be used, but one of the following self-contained water recirculation systems is recommended:

    E4860. Recirculating heater/chiller to control heating and cooling cycle (please specify voltage).

    Bonded chamber seals – Nitrile or EPDM?

    The E3100 is fitted with a standard with nitrile bonded window and door seals. Nitrile is a good general material due to its ability to withstand attack by solvents such as ethanol. However, if acetone is used as the transition fluid then the EPDM seals have been found to be more resistant to chemical attack by that solvent.

    If you are planning to use acetone as the transition fluid, please state this on the order and EPDM bonded seals will be fitted.

    For existing instruments both Nitrile and EPDM bonded seal can be ordered as spares items.

    E3100-060. Seals set for E3100 (Nitrile).

    E3100-060/EPDM. Seals set for E3100 (EPDM).

    E3100 Critical Point Dryer

    Site Requirements – please refer to operating manual for full details

    The apparatus should be positioned in the laboratory with convenient access to:

    • Hot and cold water supply (if the optional E3500 Thermocirculator or E4860 Recirculating Heater/Chiller is not used).
    • Mains power supply (for E3500 and E4860 only).
    • Fume cupboard or window, or an area of good ventilation.
    • Suitable safe location of the COsiphon cylinder.

    Liquid carbon dioxide (CO2) requirements

    The E3100 requires a cylinder of liquid CO2 fitted with a siphon tube (indicated by a vertical white stripe on the cylinder). If there is any doubt regarding the presence of a siphon tube, advice should be sought from the gas supplier.

    Cylinder connection threads vary from country to country and even between manufacturers in the same country. For example, the transfer pipe supplied is fitted with British Standard Pipe (BSP) and 0.86 x 14 TPI union. These are standard threads for the UK and generally in the rest of the world, but will not fit cylinders in the USA.

    An E3000-US kit should be specified for use within the USA, which includes a transfer pipe adaptor to fit USA cylinders. If it is deemed necessary to fabricate another transfer pipe, advice should be sought from a local supplier of high-pressure fittings.

    Heating and cooling

    Use a mixer to the laboratory hot and cold water outlets, terminating with a 6 mm Ø hose connection for the PVC tubing supplied. A Y-piece connected to the hot and cold water taps is also suitable.

    The E3100 requires both hot and cold water during the operating cycle. Cooling the chamber facilitates filling of the work chamber with liquid COand heating is required to raise the fluid temperature above its critical point.

    Good control of the water temperature is essential for good results, hence the recommended use of the E4860 Recirculating Heater/Chiller which gives precise control of cooling and heating.



    Judges House, Lewes Road,
    Laughton, East Sussex.
    BN8 6BN

    +44 1323 810981

    [email protected]


    Working Hours

    8.30 – 5.00 pm Mon – Thu
    8.30 – 4.00 pm Fri

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