MKS Stabil-Ion 370 Series, Инструкция по эксплуатации, Страница: 39 / 122

3 Installation
3-3
Series 370 Stabil-Ion Instruction Manual - 370119
■
Avoid contaminating the Stabil-Ion Gauge.
Do not touch the port. Do not talk directly at
an open vacuum port. Follow good vacuum
practice.
■
To minimize the possibility of leaks with
ConFlat
flanges, use high strength stainless
steel bolts and a new, clean OFHC copper
gasket. Avoid scratching the seal surfaces.
Do not use nonmetal gaskets.
■
After finger tightening all bolts, continue
tightening about 1/8 turn in crisscross order,
e.g., 1, 4, 2, 5, 3, 6, 4, 1, 5, 2, 6, 3, 1
…
. until
the flanges are in contact. After contact,
further tighten each bolt about 1/16 turn.
3.3 Convectron Gauge Installation
Under certain conditions, dangerous high voltage can be coupled directly to an ungrounded
conductor through a gas almost as effectively as through a copper wire connection. This hazard,
which is not peculiar to this product, is a consequence of the ability of an electric current to flow
through a gas under certain circumstances. A person may be seriously injured, or even killed by
merely touching an exposed ungrounded conductor at high potential.
When high voltages are used within the vacuum system and the Convectron Gauge envelope is not
reliably grounded through its vacuum connection, either a separate ground wire must be added, or
the envelope must be shielded to positively prevent human contact. The gauge envelope may be
grounded by using a metal hose clamp on the gauge connected by a #12 awg copper wire to the
grounded vacuum chamber.
High voltage can couple through a gas to the internal electrodes of a gauge. Do not touch the
exposed pins on any gauge installed on a vacuum system where high voltage is present.
Cleanliness pays. Keep the port cover in place until moments before installation.
For proper operation above about 1 Torr, install Convectron Gauges with the gauge axis horizontal.
To minimize pressure indication errors, avoid installing the Convectron Gauge where it will vibrate.
Vibration causes convection cooling of the sensor and will cause the pressure indication to be high.
Figure 3-2 Stabil-Ion Gauge with Connector
and Guard
When high voltage is present, all exposed conductors of a vacuum must be
maintained at earth ground.
Connector collar must be locked with integral
pin guard on ionization gauge tube BEFORE
gauge is turned on.