Shellab SCO2W-2 - Manual (Page 12)

12
5.9 CO
2
Supply System and Control System: The CO
2
system is rated for pressures between 15 to
20 PSI which should never be exceeded at any time. Prior to any attempt to hook up or run the CO
2
control system, the water jacket must be filled and the temperatures adjusted as noted in section 5.7.
Figure 3
A. The CO
2
inlet fitting is located at the back of the unit near the top (see Figure 3). It is
marked CO
2
TO CHAMBER. A supply hose with in-line CO
2
filter (supplied with your
accessories) connects from the fitting to a CO2 tank and regulator. When the 20 PSI tank is
empty its output pressure gauge will indicate 15 PSI. At this time the empty tank can be
replaced. Note that there are no alarms to indicate when the tank is empty, so operators
should monitor gas consumption.
B. It is highly recommended that a good quality 0-60 PSI output range DUAL STAGE pressure
regulator be used on the CO
2
tank. The dual stage regulator will have two pressure gauges.
The high pressure gauge (0-4000 PSI) will indicate the pressure within the tank. The low
pressure gauge (0-60 PSI) will indicate the output pressure on the supply hose to the
incubator. Do not use single stage regulators. They will not supply a stable pressure. Just
because a regulator has two gauges does not mean that it is a dual stage regulator. Insure
that you are using a dual stage regulator.
C. It is normal for the high pressure gauge on your regulator to start out reading 800 to 1000
PSI with a full tank. The reading will drop to 500 to 800 PSI quickly and will stay there for
most of the duration of the tank. At the end of use the pressure will drop quickly to zero to
indicate that the tank is completely empty. Pure CO
2
is in a liquid state in the tank, and a
constant vapor pressure is generated in the tank above the liquid level. The CO
2
is drawn off
of the top as a gas. The same vapor pressure is maintained as long as any liquid is left in
the tank. When the last of the liquid has evaporated into gas then the pressure will drop
rapidly as the gas is drawn off.
D. Only medical grade CO
2
should be used in your incubator. The use of any lesser grade may
damage your incubator and void your warranty.
E. The micro processor CO
2
control system interprets the information from the CO
2
sensor,