General Description - LEEC GA2000 Operating Instructions Manual

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GENERAL DESCRIPTION

Thank you for choosing LEEC. We trust your purchase will give you many years of
trouble-free use.
1.1 CO2 CONTROL
The CO2 concentration is controlled to a preset level with an accuracy of better
than 0.2% CO2 in air. The CO2/air mixture is continuously monitored and the
current chamber %CO2 is shown on a digital display. An Infrared (IR) CO2
sensor is used to detect the CO2 levels. If the CO2 level is below the required set
point, the control system opens a solenoid valve to inject CO2 gas into the chamber
to bring the chamber atmosphere back to the set level. When the door has been
opened, two-stage recovery of the CO2 level starts. This is achieved by controlling
both coarse and fine flow of CO2 into the incubator chamber until a preset CO2
level has been reached. The fine flow then brings the CO2 level gently up to the
correct %CO2 set point without overshooting. Whilst the door is open, the chamber
circulating fan, heaters and CO2 inlet solenoid valves are automatically shut off to
prevent wastage.
1.2 HEATING
Low wattage heaters are bonded to the outer surface of the inner chamber, using a
LEEC patented arrangement. A door heater prevents the inner glass door(s) from
condensating during high humidity operation. This keeps the view into the chamber
clear.
1.3 COOLING
A cooling coil is built in to your incubator which, when connected to a LEEC Self
Contained Recirculating Cooler, allows the incubator to operate at temperatures
near or below ambient.
1.4 TEMPERATURE CONTROL
The temperature is accurately controlled by a LEEC microprocessor system.
Multiple sensors inside the chamber and door ensure fast recovery and very stable
control. Users are able to adjust the temperature set point, low and high alarm
levels, alarm delay time and the over temperature safety cut out.
1.5 CIRCULATING FAN
A fan located at the top of the chamber blends the chamber atmosphere. This
circulation fan ensures that the mixture of gas is precise, which is essential for
sampling purposes. A small amount of heat produced by the fan raises the
chamber temperature by approximately 5° C. A door micro switch stops the fan
when the outer door is opened.
1.6 HUMIDITY
Very high humidities up to approximately 98% RH are achieved by flooding the
base of the chamber with distilled water to a depth of approximately ½ to 1 Cm.
Alternatively, the chamber can be used "dry" with no additional water without the
need for recalibration.
1.7 HIGH TEMPERATURE DECONTAMINATION (Research models only)
Models GA2000 and GA3000 are fitted with a high temperature decontamination
facility as standard. An additional heating element raises the chamber air
temperature to approximately 95° C to decontaminate the chamber. This can be
performed as often as you like. See section 11.0 for more details.
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