Carbon Evaporators by nuhman10

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									USING THE AUTO 308 CARBON EVAPORATOR
Last updated 03/10/2006


- Turn on the water pump. The pump is located underneath the table on the left.
- Turn the switch labeled “~” on the evaporator from 0 to 1 - this turns on the turbo pump. Make
sure that on the speed light display on the right panel both the orange and then green lights turn
on. This may take a few minutes.
- The display will read "POWER FAIL" hit the ''reset'' button and the display will change to
''STANDBY.''
- Press the ''start'' button and the display will go through the following: ''PUMPS ON, BACKING,
TURBO START, SEALED.''
- When the display reaches ''SEALED'' press the ''vent'' button and allow the chamber to come to
atmosphere (~+3 mBar).
- Lift the lid off of the jar and fix it in a vertical position, inserting the pin to lock it in place.
- Remove the plastic shell and the bell jar.
- If the carbon needs to be replaced, detach the copper wire, then detach the mount. To remove
the carbon, pull the copper back and loosen the carbon holder nut with the appropriately sized
Alan wrench – note that you turn clockwise to loosen this nut if you are pulling the carbon toward
yourself. Slide the carbon rod out and replace it with a new one such that when the carbon
holder is retracted half way the tip of the carbon is about a millimeter from contacting the blunt
carbon. Retighten the carbon holder and mount it back into the evaporator so the carbon faces
downwards. Retighten the screws for the mount and the wire.
- Prepare your specimen. Our convention is to align three/four mica sheets, all with the upper left
corner cut off, around the edges of the Petri dish with a small paper tent seated in the middle.
When you have the proper arrangement, center the Petri dish beneath the carbon rod – try to
align it from two different angles to assure that it’s centered. NOTE!!!!!! Always wear clean gloves
when working inside of the bell jar. NEVER touch the inside of the bell jar or the stage area with
your bare hands.
- Carefully replace the bell jar and the plastic shell, then remove the pin from the lid and lock it
into place.
- Press firmly down on the lid and press the ''cycle'' button – once you hear two clicks, you can
remove your hand. The display will read “ROUGHING”. If the message “ROUGHING FAIL”
appears, press “reset” and then “cycle”. When the pressure reaches 9x10-3 the display will read
“PUMP DOWN”, and then “FINE PUMPING”.
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- Allow the vacuum to come down to at least 1x10 before starting to evaporate. This will take
about 30 min.
- Turn the LT (low tension) knob from 0 to LT.
- Slowly turn the dial up to ~5 and watch for the carbon rod to glow. Watch closely and when you
see small sparks coming off the carbon, leave the dial at it’s location for about 1 second before
turning it down to 0.
- Repeat this step as many times as is needed to achieve the desired carbon thickness. Use a
piece of filter paper on which carbon has previously been evaporated as a reference to determine
how dark the paper should appear. Note that the paper in the apparatus will appear slightly
darker than it actually is.
- When desired carbon thickness is reached, turn the LT knob to 0.
- Press the ''vent'' button. Remove specimen, lock the bell jar and press “cycle'' button.
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- When the vacuum is at least 3x10 press the ''seal'' button, then press the ''stop'' button.
- The display will then read “TURBO STOP.”
- Wait until the display reads “STANDBY” the switch the evaporator from 1 to 0.
- Allow 30 min. before switching off the water pump.

								
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