JPS636681Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the pressure vessel of a critical point drying device for preparing samples for scanning electron microscopy.

The critical point drying device stores a sample that has been dehydrated, fixed, and replaced with an appropriate reagent in a pressure vessel.
This device dries the sample by injecting a mediating solvent such as liquid carbonic acid or liquid freon into the sample, and heating the mediating solvent so that the mediating solvent passes through a mixed state of liquid and gaseous phases and then transitions to the gaseous phase. In such an apparatus, when introducing liquefied gas as a mediating solvent into a container, it is necessary to check the liquid level to see if the container is filled with a sufficient amount for processing. In conventional equipment, a transparent viewing window is installed on the top lid of the pressure vessel that houses the sample, and while adding illumination with a penlight, the inside of the vessel is peered into and the scale placed against the vessel wall or wall is observed to check the liquid level. ing.

However, in the case of carbon dioxide gas, which is usually used as a liquefied gas, the pressure inside the container is over 100 atmospheres, so the observation window cannot be made very large. In practice, it is very troublesome to illuminate and observe through such a small window at the same time, so the confirmation of the liquid level is often omitted and the next operation is started. As a result, the liquefied gas is not injected into the container at all, or the drying process is carried out with an insufficient amount, which often results in the valuable sample being wasted.

The present invention proposes a pressure vessel for a critical point drying device that overcomes the above-mentioned drawbacks.

FIG. 1 is a sectional view showing one embodiment of the present invention.
is a pressure vessel with a pressure resistance of over 100 atmospheres. The upper surface of this container constitutes a lid 2, which can be attached to and removed from the main body, and a sample can be inserted or taken out by removing this lid.
A transparent window 3 made of a glass plate or the like is firmly and airtightly fixed to the center of the lid. A transparent window 4 is also fixed to the lower surface of the container, through which light from a lamp 5 provided outside is introduced into the container. 6 is a liquefied gas introduction pipe, and 7 is a vaporized gas discharge pipe. 8 is a scale engraved on the inner wall of the container and is used to check the liquid level.

In the embodiment shown in FIG. 2, the position of the window 4 is changed to the side of the container, and the other structure is the same as that in FIG. 1.

With this configuration, even if the viewing window 3 is small, illumination light can be introduced into the container through the window 4, making it extremely easy to observe and check the liquid level. There is no need to worry about omitting something, and there is no need to waste valuable samples.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing one embodiment of the present invention, respectively. 1...Pressure vessel, 2...Lid, 3...Peephole,
4...Lighting window, 5...Lamp, 6...Liquefied gas introduction pipe, 7...Evaporative gas discharge pipe, 8...
scale.

Claims (1)

[Scope of utility model registration request] A sample that has been dehydrated, fixed, and replaced with a reagent is stored in a pressure vessel, a mediating solvent such as liquid carbonic acid or liquid Freon is injected, and the mediating solvent is heated to change the liquid phase to a mixed state of liquid and gas phases. A pressure vessel of an apparatus for drying the sample by transferring it to a gas phase through a pressure vessel, a part of which is equipped with a transparent window for observing the inside, and a lamp placed externally in another part of the vessel. A pressure vessel for critical point drying equipment equipped with a transparent window to introduce light from inside.