Instrument Instructions
Instructions for Denton DCP-1 Critical Point Dryer
Transitional fluid: Liquid CO2
Critical temperature: 31.1° C
Critical pressure: 1073 psi
- Load specimens into drying chamber.
- Lower top closure yoke below chamber flange.
- Turn yoke counter-clockwise to engage flange.
- Tighten hand knob.
- Immerse chamber and exhaust valve in water bath filled with water from tap at 15-25° C.
- Open main CO2 tank valve all the way. Use tank indicated.
- Turn on/off switch to on. This switch controls inlet valve for CO2.
- Slightly open chamber exhaust valve by turning hand knob behind chamber and slowly bleed off CO2 maintaining pressure at about 900 psi on pressure gauge. It will be necessary to open exhaust valve slightly further periodically.
- Continue to bleed off CO2 for 5-10 min or until odor of intermediate fluid disappears. If specimens are large, seal chamber for 15-30 min and repeat bleeding process.
- Close exit valve.
- Close inlet valve by turning switch to off.
- Close main tank valve.
- Remove water and fill water bath with water from tap at 50° C.
- Immerse chamber in water bath. As chamber warms, pressure should rise to about 1650 psi.
- Vent chamber slowly by opening exhaust valve slightly. Adjust rate of flow to allow a drop of about 100 psi/min.
- Remove water and dry outside of chamber thoroughly.
- Open chamber by unscrewing hand knob, rotating yoke clockwise and lifting top closure up and away from chamber. Remove specimens.
- Store in desiccator.