Shellab BACTRON600 - Manual (Page 26)

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OPERATION (CONTINUED)
The Over Temperature Limit System
The OTL is a mechanical heating control backup system included with each incubator, and which
operates independently of the
incubator’s digital temperature c ontroller board. The OTL is intended
to be set to approximately 1 ° C above the user-selected temperature set point stored in digital
controller board. The OTL prevents runaway heating in the event that the main controller fails while
in its heating mode.
If the incubator’s temperature exceeds to the OTL limit setting, a red pilot light indicator will
illuminate and an audible alarm will buzz. The OTL System will depower the incubator’s heating
element, and continue to do so as long as the temperature remains higher than the OTL setting.
Manometer Pressure Gauge and Check Valve
The water-filled manometer in the workspace chamber serves as a visual pressure gauge, as well
as a venting check valve during instances of excess overpressures.
Figure 7: Manometer Components
An increase in atmospheric pressure inside the workstation drives down water within the
Manometer relative to a pair of reference and refill rings. Under normal operating conditions the
workstation’s overpressure displaces a -half inch of water (0.5cm). Excessive pressure will cause
the water to bubble as chamber atmosphere is vented through the manometer and out of the
workstation. This helps prevents damage to workstation gaskets. The manometer exhaust vent is a
port consisting of a transparent tube and black O-ring located on the back, right side of the
BACTRON.