In all gauges of the particles stream measurement based on molecules ionization of, electron emission from the heated tungstic string is used. Electrons are accelerated in space the cathode- grid (anode) between which the voltage 150 … 200 V is applied. The grid can to have the form of a spiral, the cylinder or a wire electrode. As a collector the cylinder, a disk or simply wire on which the negative voltage 20 … 50В moves is used. The gauge mount so that the collector of ions and an entrance aperture have been turned to the evaporator. The distance from the evaporator up to the gauge can be the same, as from the evaporator up to a substrate or less than it with the purpose of increase in sensitivity. The example of such gauge offered by Gned and Perkins is brought in figure 2.1 [9].
Figure 2.1. Ionization gauge offered Gned and Perkins.
Ions current 
, created by particles collision with electrons, it is
possible to write down in the form of:
, (2.1)
where 
- concentration of neutral
vapor particles, sm-3 inside of the gauge; 
- constant defined by the
gauge design.
Gauges of particles stream measurement, the pressure of particles based on effect, have been offered Noygebauer in 1964, however till now they have not found wide application. In figure 2.2 various designs of such gauge are brought. In both designs the light thin-walled aluminium cylinder which is mounted away from a source of particles and partially shielded from vapor is used. The surface of the cylinder opened to the evaporator is subject to influence of evaporated substance molecules which transfer it the impulse. In Bivit design the cylinder is installed on an axis and can freely rotate, whereas in Noygebauer design the cylinder is suspended on a wire which force of a twisting is directed aside, opposite to rotation. Thus in the first design the cylinder rotates all time while the sprayed atoms collide with it. In the second design the cylinder turns on a corner defined by the condition of equality of the rotating moment and force of string twisting. In both variants for clearing fluctuations it is used magnetic absorber. Bivit has derived the equations connecting sedimentation speed and the indication of gauges.
In case of the
cylinder suspended on a string, speed of sedimentation 
is proportional to
a corner of string turn 
:
, (2.2)
where 
- constant of suspension
twisting; 
- density of the besieged substance; 
- average particles speed;
- radius of the cylinder;
- height of the cylinder.
In case of the cylinder installed on an axis, speed of sedimentation is
roportional to angular speed 
. It is difficult to measure this size if to not take
advantage of the impulses account methods. Thus use integrating device which
allows supervising conveniently quantity of the besieged substance if the full
number of turns of the cylinder
is known:
, (3.3)
where 
- weight on unit of the
area of the wall or butt-end; 
- constant of time of the braked rotor.
Figure 2.2. Designs of vapour stream gauges, based on effect of the molecules pressure: with a string of the twisting, offered by Noygebauer; with an axis of the rotation, offered by Bivit.
At comparison of both variants it is necessary to note rather big persistence of the gauge with the suspended cylinder which, hence, cannot register fast changes in dispersion speed. The same is peculiar also to the design with the cylinder installed on an axis. Besides last design has also other lack connected by that some minimal size of a stream for overcoming friction of the bearing is required.
The general advantages of gauges of both types are simplicity of their design, independence of indications of residual gases pressure value, of preliminary besieged substance quantity and absence of fine tuning of zero position. Basically designs are not necessarily limited by a cylindrical rotor; rotating disks which can be placed more close to substrates can be used also.
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