Tousimis Critical Point Dryer Instructions
CAUTION, HIGH PRESSURE---WEAR SAFETY GLASSES
DO NOT ADJUST VALVES ON UNIT! THEY ARE PRESET!
LOADING THE SAMPLE
- Turn on the power switch on the right side of the CPD, vent light comes on. Let warm up 3-5 minutes.
- PRESSURE GAUGE should read 0. If it doesn't, get an EML staff member. Never attempt to remove the nuts when the specimen chamber is under pressure.
- Remove specimen chamber door and place enough 100% ethanol in the specimen chamber to cover your samples. Use the funnel to pour the ethanol in. Avoid spilling ethanol on the O-ring Do not fill all the way as your specimens will displace some of the ethanol.
- Transfer the specimen to the chamber.
- Check that the chamber o-ring is seated in the groove. Wipe off any excess ethanol.
- Carefully fit the chamber door over the three bolts, making sure the bump is facing up and at the 6:00 position.
- Tighten the three nuts each in turn with equal pressure. Just make them finger tight, don't over tighten.
PURGING THE CHAMBER
- Open the CO2 TANK VALVE completely.
- Press the COOL BUTTON. Green LED will go on and cooling continues to zero C when it stops automatically.
- Press the FILL BUTTON and the CPD will fill with LCO2. The CPD is now in automatic mode and will cycle through with filling, purging, heat, bleed, and vent cycles. Each LED will light up in turn on the unit as it progresses with each step of the cycle. It should take 40 minutes to complete.
- After venting is complete (3-4 minutes), pressure guage should read zero.
- Close the CO2 TANK VALVE.
- Loosen the three knurled knobs by hand (never use tools), and remove the specimen chamber door.
- Take out your sample and place it in a dessicator until you are ready to mount it to the stub.
- Make certain the specimen chamber is clean and the o-ring is in place and in good condition.
- Replace door and tighten the nuts by hand.
- Check that the CO2 TANK VALVE is closed.
- Turn off the power switch of CPD.
- Sign the log book.