pg. 8
Transducer installation (mechanical)
Do not use or install the 910 transducer where the following conditions occur:
- Temperatures lower than 0
o
C or higher than 40
o
C
- Corrosive or explosive gases
- Direct sunlight or other heat sources
Process compatibility
The 910 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 910 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 910 transducer and its sensor design can be mounted in any
orientation without compromising accuracy.
Explosive Environments
The MicroPirani sensor filament is kept at a low temperature of only 35
o
C
above ambient temperature, however, in case of a malfunction the sensor
element can exceed normal operating temperature and consequently the
transducer should not be used in explosive environments.
Temperature
The 910 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
o
C (185
o
F) when the power is turned off.
Contamination
Locate and orient the 910 where contamination is least likely.
The MicroPirani sensor has a low filament
temperature of only 35
o
C above ambient temperature; therefore, the MicroPirani is less prone to
contamination by cracking products from fore vacuum pump oil.
If the transducer is backfilled with a liquid (like pump oil) the sensor element is likely
permanently damaged. The transducer cannot be cleaned using solvents.
Vibrations and instant air inrush
The 910 sensor elements are 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 910 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.
Pressure range
The standard 910 transducer is internally sealed with elastomer viton sealing and is intended for use in the
pressure range 1×10
-8
to 1500 Torr.
