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Crytical point dryer (Hitachi HCP-2) Operation manual 2014. 6. 2
1. The preparation of this instrument
1. Lead out the exhausting hose of the liquefied carbon dioxide to the outdoor through the window.
2. Rotate anticlockwise the cap, to remove the cap from the chamber.
When the cap is considerably tightened, the user can use the wrench to remove the cap.
3. Clean the joint part between the cap and the O-ring carefully.
Clean the glass parts and other parts.
4. Clean the inner wall of the chamber and the O-ring carefully.
Don’t use an organic solvent such as ethanol for the cleaning of the O-ring.
Don’t leave the wastes such as the absorbent cotton in the chamber.
5. Put the level into the chamber, and then cover the chamber with the cap.
2. The precooling in the chamber
1. Close the INLET valve fully, and open the main cock of the gas bombe.
2. Turn on the instrument with the POWER switch: the POWER lamp is turned on.
3. Set the chamber temperature to 5°C, using the TEMP.CONTROL knob.
4. Wait for several minutes, until the present value of the chamber temperature reaches the setting value.
When the chamber temperature reaches the setting value, the green lamp and red lamp light alternately.
The user has to prepare the sample.
3. The insertion of the sample
1. Remove the cap from the chamber.
2. Cover the upper side and bottom sides of the sample basket with the filter papers.
Put the sample into the sample basket, and close the lid.
3. Put the sample basket rapidly into the chamber (The level is kept in the chamber).
4. The injection of the liquefied carbon dioxide and the replacement 1. Close the EXHAUST valve and the LEAK valve securely.
Open the INLET valve slowly, and then fill the vessel 50-80% full with the liquefied carbon dioxide.
This process is continuously repeated three times.
2. Check the sample basket position and the liquefied carbon dioxide volume through the peephole.
By opening the EXHAUST valve slowly, exhaust the liquefied carbon dioxide.
In this process, the user has to prevent the exposing of the sample from the liquid surface.
Subsequently, close the EXHAUST valve, and then open the INLET valve, to inject the liquefied carbon dioxide again.
Replace fully the air with the liquefied carbon dioxide in the chamber, by repeating this
2 process.
3. Open further the INLET valve slowly, fill the vessel 80% full with the liquefied carbon dioxide.
5. The evaporation and the exhaust of the liquefied carbon dioxide
1. Rotate the TEMP.CONTROL knob, to set the temperature to 35-40°C.
The pressure rises more than 73kg/cm2 (the critical pressure), at the setting value of temperature (Confirm the pressure).
<When the pressure does not reach 73kg/cm2, the shortage of the liquefied carbon dioxide volume possibly causes the low pressure.>
Set the temperature to 5°C, using the TEMP.CONTROL knob, and then the user can retry the operation mentioned above (from 4-3.).
3. Wait for 3-5 minutes at the temperature that reaches the setting value.
4. Open the LEAK valve, to exhaust the liquefied carbon dioxide at a rate of 2-3L/min.
Exhaust further the liquefied carbon dioxide, until the pressure gauge indicates zero Pa.
6. The collection of the sample
1. Rotate the TEMP.CONTROL knob, to set the temperature to 20-22°C (room temperature) 2. Remove the cap, and take the sample basket from the chamber.
7. After completing the operation
1. Turn off the instrument with the POWER switch.
Close the all valves.
Clean the chamber (see to 1).
8. The removal of the gas from the hose connected with the bombe
1. Close the main cock of the gas bombe, and tighten fully all valves and the chamber cap with the wrench.
2. Open the INLET valve and the EXHAUST valve, to remove the gas from the chamber.
3. After the removal of the gas, close the INLET valve and the EXHAUST valve.
4. Loose the chamber cap.
Pull in the hose for the exhaust of the liquefied carbon dioxide (from the outdoor to the indoor).
Notice: The user has to use the instrument carefully, to prevent the misoperation.
Because the chamber pressure rises considerably during the operation, the misoperation often causes the accidents.