Bactron User Group > Chamber Operation  »   How do I make my chamber Anaerobic?

Prior To Purging The Chamber you need to do the following:
1. Turn Power switch to the “O” (Off) position.
2. Place about six oxygen indicators inside the system. Place one unopened indicator
in the incubator, and place one unopened indicator in the work area. The others can
be stores in the work are for future use.
3. Place catalyst in the chamber. For more information about the correct placement of
the catalyst, see Section 6.0. Catalyst Cartridge page 11 and 12.
4. Open the incubator doors before leaving the chamber. This allows the incubator to
become anaerobic also.
5. Put armport doors in place.

NOTE: The Bactron chambers have an efficient method for sealing the chamber by
utilizing the Armport doors as shown in Figure 3 on page 4. The tightening knob
on the Armport doors should be snug, DO NOT OVER TIGHTEN. Damage can
occur if too much force is placed on the Armport door assembly. When the knob
just begins to “grab”, the tightening bolt has reached its maximum point. Over
tightening will cause the bolt to slip inside the handle and cause leakage.

Once you have completed the steps above, you need to purge the chamber. To do this, do the following:

Purging the Chamber
6. Turn Power Switch to the “I” (On) position.
7. Note the reading on the gas regulator.
8. Loosen the right armport door to create a small leak. (Remove sleeves from the
armports if they have been placed there. This will make it easier to adjust the
armport doors to create the proper leak.) Adjust the doors so that the CHAMBER
GASSING light flashes ON and OFF for equal periods. It is important that the gas
flows into the chamber in “pulses” rather than as a “stream”. If the gas “streams”, it
tends to go to the open door only.
9. Bleed the gas mixture through the chamber until the reading on the tank regulator
gauge is 300-400 psi less than the original reading. Normally, it takes 1-1/2 to 2
hours to flush out all atmosphere from the chamber.
10. After the gas purge, tighten the armport doors to prevent leaking. The CHAMBER
GASSING light will turn off, flow of gas into the chamber will stop, and the water
level difference in the manometer should again be approximately ½” and should
remain stable.
11. At this point it is important to check if the chamber is completely anaerobic before
using it. Check this by first replacing the sleeves on the armports, and the entering
the chamber.
12. Once inside the chamber, open one indicator strip in the incubator, and one strip
in the work area.

NOTE: Please note and follow the directions for use for the type of indicator
strip you are using. If the strips indicate that the atmosphere is anaerobic, the chamber is ready for
use. If the strips indicate an aerobic or slightly aerobic atmosphere, then exit the
chamber. Create a small leak as detailed in Step 8. Flush an additional 100-
200 psi through the chamber. After this step, proceed to step 11, until indicator
strips indicate an anaerobic atmosphere. The gas flowing through the chamber may cause previous indicator strips to dry out. Use fresh indicator strips stored in step 2 each time you test the
atmosphere.

NOTE: During the initial purge you may notice heavy condensation within the chamber.
This is due to catalytic formation of water from hydrogen gas and oxygen initially in the
chamber. Most of this condensation will dissipate by the end of the gas purge cycle.

CAUTION: The catalyst cartridge will be HOT at this point. If you must touch it for any
reason, use extreme care.