902B Abs Piezo
Operation manual
8
Transducer installation (mechanical)
Process compatibility
The 902B transducer is intended for use in relatively clean environments. The transducer cannot be used in
corrosive environments like a semiconductor etch process chamber where aggressive gases like fluorine are
used.
If the 902B transducer is located close to a gas source connection like a flow controller or leak valve the
transducer pressure measurement can be higher than the actual chamber pressure. Location close to a
pumping system connection can cause a lower pressure measurement than actual chamber pressure.
The 902B transducer and its sensor design can be mounted in any
orientation without compromising accuracy.
Temperature
The 902B has an active and individual sensor temperature compensation
circuit that ensures accurate measurement in a wide temperature range.
For best measuring performance avoid large temperature gradients and
direct cooling like air-condition air stream or direct heating like a pump
exhaust stream.
Bake-out
The transducer electronics can withstand 85 °C (185 °F) when the power
is turned off.
Contamination
Locate and orient the 902B where contamination is least likely.
Vibrations and instant air inrush
The 902B sensor element is extremely robust to mechanical forces like vibration and G-forces.
The sensor element cannot be damaged by fast and repeated pressure cycles or instant inrush of air.
Vacuum connections
The 902B transducer is available with different types of vacuum fittings. When mounting the transducer
always ensure that all vacuum sealing items and surfaces are clean, without damage and free of particles.
Do not touch the vacuum flange sealing surface.
If the transducer will be exposed to pressures above atmospheric pressure, make sure that proper
vacuum fittings are used. Ensure that the internal system pressure is at ambient pressure
conditions before opening the vacuum system and removing any connections.
