971B UniMag™
6
Operation manual
Description
The 971B UniMag™ vacuum transducer offers a wide measuring range from 1×10
-8
to 5×10
-3
Torr and is
based on measurement of cold cathode ionization current.
The 971B is designed for general purpose pressure
measurement and control as a standalone unit or with the
PDR900 display and controller unit.
The transducer uses RS232 or RS485 digital communication
interface for setup of transducer parameters and to provide
real time pressure measurement.
The 971B has up to three mechanical relays which can be
used for process control, for example interlocking valves or pumps. The analog
voltage output can be interfaced to external analog equipment for pressure readout
or control.
Sensor technology
The cold cathode inverted magnetron utilizes a high voltage anode,
cathode and a permanent magnet. Electrons are accelerated towards the
anode and will ionize molecules by collision. The magnetic field deflects
the electrons, causing them to spiral as they move across the magnetic
field to the anode. This spiraling movement increases the opportunity for
them to encounter and ionize the molecules.
The ionization of the molecules creates an electric current as a function of
the pressure.
Applications
The 971B can be used in many different vacuum applications within the
semiconductor, analytical and coating industries:
•
General vacuum pressure measurement
•
Coating
•
Mass spectrometer control
•
System process control
•
Sense abnormal pressure and take appropriate security measures using set point relays
•
Control system base pressure
Disposal (European Union only)
The 971B transducer is manufactured according to the RoHS directive.
For the benefit of the environment, at the end of life of the 971B, it should not
be disposed in the normal unsorted waste stream. It should be deposited at an
appropriate collection point or facility to enable recovery or recycling.