Leica Biosystems ASP300 S - Manual (Page 13)

14 Leica ASP300 S
2.3 Safety features on the instrument
In the case of power failures or other processing problems the Leica
ASP300 S incorporates specimen protection features such as a fluid level
sensor and sophisticated software controls which ensure that processing
can be completed successfully without damage to the tissue specimens.
Overpressure protection
• When power is off the air pump and air valves default to a safe condition
(retort vented, no pressure generation).
• If the pump is not stopped at the correct moment during the pressuriza-
tion, the power supply is interrupted by a separate electronic circuit.
• In addition, there is a safety relief valve that vents all excess air pump
output to atmosphere.
Overcurrent protection
• Overcurrent conditions are protected against by both the main fuse and
the separate heating power fuses.
Overheating protection
An error is indicated and all heating is stopped by the microprocessor
–control if the instrument detects any of the following conditions:
• Abnormally high temperature (>75 °C)
• Contradictory results of the temperature sensors
• Failure of one or more heating power control components
• If the microprocessor fails to interrupt heating power, independent tem-
perature limiting hardware circuits limit the temperature rise to a safe
level.
• If the temperature limiting circuits malfunction, an independent hard-
ware thermal fuse circuit cuts power to the heating elements.
Over vacuum protection
• The vacuum system is not capable of generating a dangerous vacuum
condition.
Overcurrent protection
• Overcurrent conditions are protected against by both the main fuse and
the separate heating power fuses.
2. Safety