ASP STERRAD 100, Service Manual

Page: 91 / 309

Vent Valve
The vent valve, a normally closed solenoid valve, is opened to admit vent
air into the process chamber during the vent stage of the cycle and to
end an aborted cycle. The valve is sized to vent the chamber from 300
mTorr to Atmospheric pressure in less than 3 minutes. When closed, the
valve does not leak through at greater than 10-6 mbar times 1 liter/sec
of helium.
Pressure Switch
The pressure switch monitors the chamber pressure sending a software
signal when the chamber pressure is over 690 Torr. There are two types,
the Whitman switch and the SMC switch (Block 2 only).
Capacitance Manometer
Located external to, and on the upper left side of the process chamber, is
a capacitance manometer with 12 VDC supply and 0-4 VDC output
corresponding linearly to 0-10 Torr. The manometer is accurate to 0.25%
of full scale, thermally stable to 3 mTorr per °C and exhibits less than 25
mTorr of zero drift long term. The linear output of the sensor also covers
the range of 10-15 Torr with a linear output signal of 4-6 VDC and an
accuracy of 2.0% of the reading. The output of this transducer goes to
the control subsystem to control events during the sterilization cycle.
Vacuum Subsystem Calibration
IMPORTANT!:
Your first step when troubleshooting a system is to verify
that the system is properly connected to the power source, and to make
sure all the subsystems are properly connected to the AC system and all
circuit breakers are on and functioning normally. Once you have
verified these things, proceed with your troubleshooting steps.
Calibration Topics:
F
Adjusting The Vacuum Switch
F
Vacuum Pump Ballast Valve Adjustments
F
Vacuum Subsystem Tests (AutoTest)
Vacuum Subsystem Calibration Vacuum Subsystem
ASP Service Guide rev. D STERRAD® 100 Sterilizer 4-5